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## Guess Paper Physics Class 11 2023

### 11th Class Physics Important Short Questions

**Chapter 1**

- Name several repetitive phenomena occurring in nature which could serve as reasonable time standards.
- Give the drawbacks to use the period of a pendulum as a time standard.
- Why do we find it useful to have two units for the amount of substance the kilogram and the mole?
- The period of simple pendulum is measured by a stopwatch. What type of errors is possible in the time period?
- Does a dimensional analysis give any information on constant of proportionality that may appear in an algebraic expression? Explain.
- Write the dimensions of pressure and density.

**Chapter 2**

- The vector sum of three vectors gives a zero resultant. What can be the orientation of the vectors?
- If one of the rectangular components of a vector is not zero, can its magnitude be zero? Explain.
- Can a vector have a component greater than the vector’s magnitude?
- Can the magnitude of a vector have a negative value?
- If A+B=0, what can you say about the components of the two vectors?
- Under what circumstances would a vector have components that are equal in magnitude?
- Is it possible to add a vector quantity to a scale quantity? Explain.
- Can you add zero to a null vector?
- Two vectors have unequal magnitudes. Can their sum be zero? Explain.
- Show that the sum and difference of two perpendicular vectors of equal lengths are also perpendicular and of the same length.
- How would the two vectors of the same magnitude have to be oriented, if they were to be combined to give a resultant equal to a vector of the same magnitude?
- If all components of the vectors A1 and A2 were reversed, how would this alter A1 x A2?
- Name the three different conditions that could make A1 x A2 = 0.

**Chapter 3**

- Can a body rotate about its center of gravity under the action of its weight?
- An object is thrown vertically upward. Discuss the sign of acceleration due to gravity, relative to velocity, while the object is in the air.
- Can the velocity of an object reverse the direction when acceleration is constant? If so, give an example.
- Motion with constant velocity is a special case of motion with constant acceleration is this statement true? Discuss.
- Define impulse and show how it is related to linear momentum.
- At what points in its path does a projectile have its minimum speed, and its maximum speed?

**Chapter 4**

- A person holds a bag of groceries while standing still, and a car is stationary with its engine running at standpoint, how the two situations are simpler?
- Calculate the work done in kilojoules in lifting a mass of 10 kg (at a steady velocity) through a vertical height of 10m.
- A force F acts through a distance L. The force is then increased to 3F and then acts through a further distance of 2L. Draw the work diagram to scale.
- In which case is more work done? When a 50kg bag of books is lifted through 50cm, or when a 50kg crate is pushed through 2m across the floor with a force of 50N?
- An object has 1J of potential energy. Explain what does it mean?
- What sort of energy is in the following: i) Compressed spring ii) Water in a high dam iii) A moving car
- A girl drops a cup from a certain height, which breaks into pieces. What energy changes are involved?
- A boy uses a catapult to throw a stone that accidentally smashes a greenhouse window. List the possible energy changes.
- When a rocket re-enters the atmosphere, its nose cone becomes very hot. Where does this heat energy come from?

**Chapter 5**

- State the direction of the following vectors in simple situations, angular momentum and angular velocity.
- Show that orbital angular momentum Lo = mvr.
- Describe what should be the minimum velocity, for a satellite, to orbit close to the Earth around it.
- Why mud flies off the tyre of a moving bicycle, and in what direction does it fly?
- Why does a diver change his body positions before and after diving in the pool?
- Explain how many minimum numbers of geostationary satellites are required for global coverage of T.V transmission.

**Chapter 6**

- Explain what you understand by the term viscosity.
- Why do fog droplets appear to be suspended in the air?
- Explain the difference between laminar flow and turbulent flow.
- State Bernoulli’s relation for a liquid in motion and describe some of its applications.
- A person is standing near a fast-moving train. Is there any danger that he will fall toward it?
- Two-row boats moving parallel in the same direction are pulled towards each other. Explain.
- Explain, how the swing is produced in a fast-moving cricket ball.
- Explain the working of a carburetor of a motorcar using Bernoulli’s principle.

**Chapter 7**

- Name two characteristics of simple harmonic motion.
- Does frequency depend on amplitude for harmonic oscillators?
- Can we realize an ideal simple pendulum?
- What is the total distance traveled by an object moving with SHM in a time equal to its period, if its amplitude is A?
- What happens to the period of a simple pendulum if its length is doubled? What happens if the suspended mass is doubled?
- Does the acceleration of a simple harmonic oscillator remain constant during its motion? Is the acceleration ever zero? Explain.
- What is meant by phase angle? Does it define the angle between maximum displacement and the driving force?
- Under what conditions does the addition of two simple harmonic motions produce a resultant, which is also simple harmonic?
- Describe some common phenomena in which resonance plays an important role.
- If a mass-spring system is hung vertically and set into oscillations, why does the motion eventually stop?

**Chapter 8**

- What features do longitudinal waves have in common with transverse waves?
- Is it possible for two identical waves traveling in the same direction along a string to give rise to a stationary wave?
- Why does sound travel faster in solids than in gases?
- How are beats useful in tuning musical instruments?
- As a result of a distant explosion, an observer senses a ground tremor and then hears the explosion. Explain the time difference.
- Explain why sound travels faster in warm air than in cold air.
- How should a sound source move with respect to an observer so that the frequency of its sound does not change?
- A wave is produced along a stretched string but some of its particles permanently show zero displacements. What type of wave is it?

**Chapter 9**

- Under what conditions do two or more sources of light behave as coherent sources?
- How is the distance between interference fringes affected by the separation between the slits of Young’s experiment? Can fringes disappear?
- Can visible light produce interference fringes? Explain.
- Explain whether Young’s experiment is an experiment for studying interference or diffraction effects of light.
- An oil film spreading over a wet footpath shows colors. Explain how does it happen?
- Could you obtain Newton’s rings with transmitted light? If yes, would the pattern be different from that obtained with reflected light?
- How would you manage to get more orders of spectra using a diffraction grating?
- Why polaroid sunglasses are better than ordinary sunglasses?
- How would you distinguish between unpolarized and plane-polarized lights?

**Chapter 10**

- Why would it be advantageous to use blue light with a compound microscope?
- One can buy a cheap microscope for use by children. The images seen in such a microscope have colored edges. Why is this so?
- If a person was looking through a telescope at the full moon, how would the appearance of the moon be changed by covering half of the objective lens?
- How the light signal is transmitted through the optical fiber?
- How the power is lost in optical fiber through dispersion?

**Chapter 11**

- Why is the average velocity of the molecules in a gas zero but the average of the square of velocities is not zero?
- Why does the pressure of a gas in a car tyre increase when it is driven through some distance?
- Specific heat of a gas at constant pressure is greater than specific heat at constant volume. Why?
- Give an example of a process in which no heat is transferred to or from the system but the temperature of the system changes.
- Is it possible to convert internal energy into mechanical energy? Explain with an example.
- Is it possible to construct a heat engine that will not expel heat into the atmosphere?
- A thermos flask containing milk as a system is shaken rapidly. Does the temperature of milk rise?
- What happens to the temperature of the room, when an air conditioner is left running on a table in the middle of the room?
- Can mechanical energy be converted completely into heat energy? If so give an example.
- Does the entropy of a system increase or decrease due to friction?
- Give an example of a natural process that involves an increase in entropy.

### 1st Year Short Questions for the Best Preparation

- Define physics and give the names of its two main branches.
- Define solid-state physics and nuclear physics.
- What are the main frontiers of fundamental science?
- Differentiate between the base units and derived units.
- What are base units? Draw their table.
- What do you mean by scientific notation? Give an example.
- Define radian and steradian.
- Explain how can we remove the effect of systematic error and random error?
- Define significant figures.
- Is zero significant or not? Explain.
- Define precision and accuracy.
- Write down the two uses of dimension analysis.
- What are the dimensions and S.I. units of the coefficient of viscosity η in the relation F = 6πηrv
- Write the dimension of the work.
- Show that the equation S= vit + 1/2at
^{2}is dimensionally correct. - Define Null vector and equal vectors.
- What is a negative vector? How B is subtracted from A?
- What is the unit vector in the direction of the vector A = 4i +3j
- Why do you keep your legs far apart when you have to stand in the aisle of a bumpy riding bus
- Prove that commutative law holds for the addition of vectors.
- You are falling off the edge. What should you do to avoid the fall?
- How vector is determined when rectangular components are given?
- Name three conditions that could make A . B=0
- Prove that the dot product of two vectors is commutative.
- Prove that vector products do not obey commutative law.
- Write two examples of vector products.
- Define torque and moment arm. Also, give physical significance to torque.
- Write two conditions for which torque is zero.
- What do you understand by positive and negative torque?
- Define torque. Write its units and dimensions.
- Define the two conditions of equilibrium.
- Define dynamic and static equilibrium.
- Differentiate between distance and displacement.
- Explain what you mean by the term velocity.
- Define the instantaneous velocity of a moving body.
- What is meant by instantaneous acceleration? Write its formula.
- How is the distance calculated from the velocity-time graph?
- State Newton’s second and third law of motion?
- Why the first law of motion is also called the law of inertia.
- Show that the rate of change in momentum for an object is equal to the applied force.
- Does a moving object have an impulse?
- Why motorcycle safety helmet padded?
- Find the relation of force due to the water flow.
- How would you find the momentum of an explosive force? Explain with one example.
- Show the range of the projectile is maximum when the projectile is thrown at an angle of 45ᵒ with the horizontal.
- What is the ballistic flight? Explain
- Write down two characteristics of a ballistic missiles.
- Derive the relation for the maximum height reached by the projectile.
- What do you understand by work and energy? Give their units.
- What do you mean by variable force? Give two examples.
- Define conservation field. Give two examples.
- Define the term power and its S.I. units.
- Derive the relation between power and velocity.
- Define kilowatt hour. Show that 1kWh = 3.6×10
^{6}J. - Write power in terms of force and velocity?
- Define work energy principle. Also write down its equations.
- What is escape velocity of an object? Write its mathematical expression.
- State the law of conservation of energy.
- How electrical energy can be obtained by using tides?
- Write down two sources of energy which are renewable.
- Name some non-conventional energy sources.
- How electrical energy be obtained by sunlight by indirect conversion method?
- What is geo-thermal energy?
- Explain briefly about residual heat of the earth.
- How energy is obtained from direct combustion and fermentation?
- How many most common methods used for the conservation of biomass, into fuel write their names?
- Show that v = rω.
- Show that a = rα.
- Can a body move along a circle without centripetal force?
- Is any work done by centripetal force?
- What does “INTELSAT” stands for?
- Define real weight and apparent weight.
- An object revolving around the earth is said to be a freely falling body. Why?
- State right hand rule to find the direction of angular displacement?
- Show that 1 radian = 57.3°
- Describe what should be the minimum velocity for a satellite to orbit close to the Earth around it.
- A lift is ascending with the acceleration “a”. Derive the expression for apparent weight of the body of mass “m” in it.
- Define weightlessness and gravity free system.
- What is a geostationary satellite?
- Write down applications of communication satellites.
- What is meant by centripetal force? How is it converted in terms of angular velocity?
- Why banked tracks are needed for turns?
- Define artificial gravity. Write down the expression for its frequency.
- Define and explain briefly drag force.
- Briefly explain viscous drag and Stoke’s law.
- Briefly explain terminal velocity.
- How an aeroplane is lifted up in the air?
- State Stoke’s law and write its formula.
- Explain the term viscosity. What is its unit?
- What is Venturi’s effect? Write only its mathematical form.
- Show that for a fluid where the speed of the fluid is high the pressure will be low.
- How a chimney works the best?
- State Bernoulli’s equation and Torricelli’s theorem.
- Define systolic and diastolic pressure.
- Define Hooke’s law. Write it in mathematical form.
- If heavy and light masses of the same size are set to vibration which of them will stop first?
- What is the difference between displacement and amplitude?
- What is the effect of amplitude on the frequency and period of a simple pendulum?
- What is meant by phase and initial phase?
- State the total energy of the vibrating mass and spring is constant. Differentiate between free and forced oscillations?
- What is driven harmonic oscillator?
- Write an advantage and a disadvantage of resonance.
- Describe the condition under which a vibrating body resonates with another body.
- Define the sharpness of the resonance.
- Write three uses of a simple pendulum.
- How resonance is produced in the tuning of the radio set?
- Define frequency and time period and relation in them.?
- What is the second’s pendulum? Find its length and frequency.
- Define damping and resonance.
- Why soldiers are advised to break their steps while marching on a bridge?
- Write and explain the electrical application of resonance.
- Differentiate between frequency and angular frequency?
- Define the term Oscillations.
- Briefly explain restoring force.
- Describe the function of a microwave oven.
- How does the mass change the time period of a mass-spring system?
- Why does sound travel faster in hydrogen than in oxygen?
- Why can microwave not detect underwater objects?
- Explain the terms red shift and blue shift in Doppler’s effect.
- Define waves and progressive waves.
- Write characteristic of stationary waves.
- Write formula of speed of sound at 00C.
- State the principle of superposition.
- How the velocity of a wave will change if “tension” is made 16 times?
- Define mechanical and electromagnetic waves.
- Write any two applications of Doppler’s effect.
- Differentiate between “an open organ pipe” and “a closed organ pipe”.
- Define Beats. Write its two uses.
- Define interference of waves. Write the conditions for interference.
- Write down effects of variation of pressure and density on the speed of sound.
- Briefly describe the principle of superposition.
- What are stationary waves and how are they produced?
- Which is richer in harmonics, an open organ pipe or a closed organ pipe?
- Define Doppler’s shift. Also, write its formula.
- What is radar?
- What is the velocity of sound in air, if the temperature of the air is 200C?
- How the velocity of stationary waves in a string is affected by changing its tension?
- Can Doppler’s effect be applied to electromagnetic waves? Give an example.
- What is an apparent change in frequency when a source is moving away from the stationary observer?
- What is an apparent change in frequency when a source is moving toward a stationary observer?
- What is an apparent change in frequency when an observer is moving away from a stationary source?
- What is an apparent change in frequency when an observer is moving toward a stationary source?
- Define Light and Physical Optics.
- Define wavefront also differentiate spherically and plane wavefront.
- State Huygens principle and its two steps.
- Define interference of light and its conditions.
- What are the conditions for dark and bright fringes in the Young double-slit experiment of interference?
- Explain thin films and also explain the darkness of the central fringe of Newton’s ring.
- Define diffraction of light.
- What is diffraction grating?
- Define X-ray diffraction. Also, write its two uses.
- Define polarization and plane-polarized light.
- Define optical rotation.
- What is the meaning of fringe spacing and on which factors it depends?
- What is the sugar solution process in polarization?
- When is white light projected through the diffraction grating and produces interference? What colors are between the bands of interference?
- Define the least distance of vision and what is the minimum value of the human distance of vision?
- Define magnification and resolving power.
- Differentiate linear and angular magnification?
- How can we measure the magnification of a simple microscope?
- Write down the formula for compound microscope magnification.
- What is an astronomical telescope; explain its working with a diagram.
- What is the meaning of eyepiece and objective lenses?
- Define the spectrometer and write down its essential parts.
- What is the use of a spectrometer?
- If an astronomer wants to study the stars which are million years away, which type of telescope they will use?
- Write down the formula of time and speed for measuring the speed of light.
- What is an optical fiber? Define its types.
- What is the principle of fiber optics?
- Explain total internal reflection.
- Write down the uses of optical fibers.
- Differentiate cladding and jacket?
- Define refractive index.
- Define Thermodynamics and describe the kinetic theory of gases.
- Describe the relationship between temperature and kinetic energy.
- Define Boyle’s law with a graph.
- Define Charles’s law, with a graph.
- What is the meaning of internal energy?
- Differentiate work and energy, and derive the formula for work done.
- Explain the first law of thermodynamics with an equation.
- Differentiate isothermal and adiabatic processes with graphs.
- Define molar-specific heat. What is the difference in molar specific heat at constant volume and constant pressure?
- Differentiate reversible and irreversible processes.
- Define the second law of thermodynamics and heat engine.
- What is the Carnot theorem and how Carnot engine works on the theorem?
- What is the meaning of the efficiency of the Carnot engine?
- Define the second law of thermodynamics in terms of Entropy.
- Define absolute temperature.

### 11th Class Physics Important Long Questions

- Define torque. Calculate torque due to force acting on a rigid body.
- Define scalar product with examples. Write down its any four characteristics.
- Define vectors product of two vectors. Also write the characteristics of vector product of two vectors.
- Derive the expression for the magnitude and direction of the resultant of two vectors, added by the rectangular component method.
- Define projectile motion. Derive relation for the following terms: i) Time of flight ii) Range of flight
- Define elastic and inelastic collision. Explain elastic collision in one dimension to show the relative velocities before and after collision are same.
- Explain the interconversion of potential energy and kinetic energy.
- Define absolute gravitational P.E. derive an expression for the absolute value of gravitational P.E of a body at a distance “r” from the center of the earth.
- When two nodes of frequencies f
_{1}and f_{2}are sounded together, beats are formed. If f_{1}> f_{2}, what will be the frequency of beats? i) f_{1}+ f_{2}ii) 1/2(f_{1}+ f_{2}) iii) f_{1}− f_{2}iv) 1/2(f_{1}− f_{2}) - Discuss effect of temperature on speed of sound. Also prove that v
_{t}= v_{0}+ 0.61t. - Write down newton’s formula for speed sound in air explain the Laplace correction by deriving the relation for speed of sound in air.
- Define Doppler’s effect. Derive apparent frequency if: a) observer moves towards the source b) observer moves away from the source
- Explain interference. Find the conditions for i) constructive interference ii) destructive interference
- What is drawback of Newton’s formula for the speed of sound and how this was corrected by Laplace? Derive the Laplace’s expression for the speed of sound and also find the value of speed of sound by using this expression.
- A disc and a hoop start moving down from the top of an inclined plane at the same time. Which one will be moving faster on reaching the bottom?
- Define artificial satellite. Explain that how real and apparent weight in an elevator for all the cases is related?
- Define rotational K.E. Also derive formula for rotational K.E of a disc and hoop coming down an inclined plane.
- Define rotational K.E. show that a disc will be moving faster than a hoop on reaching the bottom of an inclined plane, when thrown at the same time.
- What are geostationary satellites? Derive the relation for radius of geostationary orbit.
- Define Stoke’s law and show that the terminal velocity is directly proportional to square of radius of the object.
- State and prove the Bernoulli’s equation in dynamic fluid that relates pressure to fluid speed and height. State and derive equation of continuity A
_{1}v_{1}= A_{2}v_{2} - Explain the relation between total energy, potential energy and kinetic energy for a body oscillating with SHM.
- Discuss the motion of horizontal mass spring system and also derive formula for time period, displacement and velocity.
- Define pressure of a gas. Prove that P =2/3 N
_{o}< 1/2mv^{2}>. - Define first law of thermodynamics. Explain isothermal and adiabatic process.
- What is Carnot heat engine? Show that efficiency of a Carnot heat engine depends on the temperature of the hot and cold reservoirs.
- Define molar specific heat and prove that C
_{p}− C_{v}= R - Define and explain entropy with an example. Does entropy decrease for reversible process? Why absolute value of entropy cannot be determined?
- Explain Young’s Double slit experiment to study the phenomenon of interference of light.
- Explain Young’s double slit experiment. Derive the relation for position of mth bright and dark fringe from the center of the screen.
- Describe the diffraction of X-rays by crystal and derive Bragg’s equation.
- Discuss Michelson’s experiment for the determination of speed of light.
- What is compound microscope? Give its construction, working and derive the expression for the angular expression.
- What is astronomical telescope? Sketch its ray diagram, write its working and find its angular magnification.

### 11th Class Physics Important Numerical Problems

- Suppose in a rectangular coordinate system, a vector A has its tail at the point P(−2, −3) and its tip at Q(3,9). Determine the distance between these two points.
- Show that the three vectors î + ĵ + k̂, 2î – 3ĵ + k̂ and 4î + ĵ – 5k̂ are mutually perpendicular.
- The line of action of force, F = î – 2ĵ passes through a point whose position vector is (− î + k̂). Find i) the moment of F about the origin. ii) the moment of about the point at which the position vector is î + k̂.
- The magnitude of the dot and cross products of two vectors are 6√3 and 6 respectively. Find the angle between the vectors.
- A boy places a firecracker of negligible mass in an empty can of 40 g mass. He plugs the end with a wooden block of mass 200 g. After igniting the firecracker, he throws the can straight up. It explodes at the top of its path. If the block shoots out with a speed of 3.0 ms
^{−1}, how fast will they can be going? - An electron (m = 9.1 × 10
^{−31}kg) traveling at 2.0 × 107 ms−1 undergoes a head-on collision with a hydrogen atom (m = 1.67 × 10−27 kg ) which is initially at rest. Assuming the collision to be perfectly elastic and a motion to be along a straight line, find the velocity of a hydrogen atom. - A truck weighing 2500 kg and moving with a velocity of 21 ms
^{−1}collides with a stationary car weighing 100 kg. The truck and the car move together after the impact. Calculate their common velocity. - Two blocks of masses 2.0 kg and 0.50 kg are attached at the two ends of a compressed spring. The elastic potential energy stored in the spring is 10 J. Find the velocities of the blocks if the spring delivers its energy to the blocks when released.
- A bomber dropped a bomb at a height of 490 m when its velocity along the horizontal was 300kmh
^{−1}. i) How long was it in air? ii) At what distance from the point vertically below the bomber at the instant the bomb was dropped, did it strike the ground? - An SLBM (submarine-launched ballistic missile) is fired from a distance of 3000 km. If the Earth is considered flat and the angle of launched is 45
^{0}with horizontal, find the velocity with which the missile is fired and the time taken by SLBM to hit the target. - A man pushes a lawn mower with a 40 N force directed at an angle of 20
^{∘}downward from the horizontal. Find the work done by the man as he cuts a strip of grass 20 m long. - Ten bricks, each 6.0 cm thick and mass 1.5 kg, lie flat on a table. How much work is required to stack them one on the top of another?
- A 1000 kg automobile at the top of an incline 10 meters high and 100 m long is released and rolls down the hill. What is its speed at the bottom of the incline if the average retarding force due to friction is 480 N?
- A diver weighing 750 N dives from a board 10 m above the surface of a pool of water. Use the conservation of mechanical energy to find his speed at a point 5.0 m above the water surface, neglecting friction.
- When two nodes of frequencies f
_{1}and f_{2}are sounded together, beats are formed. If f_{1}> f_{2}, what will be the frequency of beats? i) f_{1}+ f_{2}ii) 1/2(f_{1}+ f_{2}) iii) f_{1}− f_{2}iv) 1/2(f_{1}− f_{2}) - A stationary wave is established in a string which is 120 cm long and fixed at both ends. The string vibrates in four segments; at a frequency of 120 Hz. Determine its wavelength and the fundamental frequency?
- The frequency of the note emitted by a stretched string is 300 Hz. What will be the frequency of this note when: a) the length of the wave is reduced by one third without changing the tension. b) the tension is increased by one-third without changing the length of the wire.
- Organ pipe has a length of 50 cm. Find the frequency of its fundamental note and the next harmonic when it is: a) open at both ends b) closed at one end.
- A tiny laser beam is directed from the Earth to the Moon. If the beam is to have a diameter of 2.50 m at the Moon, how small must divergence angle be for the beam? The distance of Moon from the Earth is 3.8 × 10
^{8}m. - Calculate the angular momentum of a star of mass 2.0 × 10
^{30}kg and radius 7.0 × 10^{5}km. If it makes one complete rotation about its axis once in 20 days. What is its kinetic energy? 4. Explain artificial gravity. - Calculate the angular momentum of a star of mass 2.0 × 10
^{30}kg and radius 7.0 × 10^{5}km. if it makes one complete rotation about its axis one in 20 days, what is its kinetic energy? - Certain globular protein particle has a density of 1246kgm
^{−3}. It falls through pure water with a terminal speed of 3.0cmh^{−1}. Find the radius of the particle. - Water is flowing smoothly through a closed pipe system. At one point the speed of water is 3.0 ms
^{−1}, while at another point 3.0 m higher, the speed is 4.0 ms^{−1}. If the pressure is 80kPa at the lower point, what is pressure at the upper point? - The radius of the aorta is about 1.0 cm and the blood flowing through it has a speed of about 30cms
^{−1}. Calculate the average speed of the blood in the capillaries using the fact that although each capillary has a diameter of about 8 × 10^{−4}cm, there are literally millions of them so that their total cross section is about 2000 cm^{2}. - A load of 15.0 g elongates a spring by 2.00 cm. If body of mass 294 g is attached to the spring and is set into vibration with an amplitude of 10.0 cm, what will be its: i)period ii)spring constant iii) maximum speed of its vibration.
- A block of mass 4.0 kg is dropped from a height of 0.80 m on to a spring of spring constant k = 1960Nm
^{−1}. Find the maximum distance through which the spring will be compressed. - A car of mass 1300 kg is constructed using a frame supported by four springs. Each spring has a spring constant 20,000Nm
^{−1}. If two people riding in the car have a combined mass of 160 kg, find the frequency of vibration of the car, when if is driven over a pot hole in the road. Assume the weight is evenly distributed. - A Carnot engine utilizes an ideal gas. The source temperature is 227
^{∘}C and the sink temperature is 127^{∘}C. Find the efficiency of the engine and also find the heat input from the source and heat rejected to the sink when 10000 J of work is done. - A reversible engine works between two temperatures whose difference is 100
^{∘}C. If it absorbs 746 J of heat from the source and rejects 546 J to the sink. Calculate the temperature of the source and the sink. - A heat engine performs 100 J of work and at the same time rejects 400 J of heat energy to the cold reservoirs. What is the efficiency of the engine?
- A Carnot engine whose low temperature reservoir is at 7
^{∘}C has an efficiency of 50%. It is desired to increase the efficiency to 70%. By how many degrees the temperature of the source be increased? - A steam engine has a boiler that operates at 450 K. The heat changes water to steam, which drives the piston. The exhaust temperature of the outside air is about 300 K. What is maximum efficiency of this steam engine?
- Calculate the wavelength of light, which illuminates two slits 0.5 mm apart and produce an interference pattern on a screen placed 200 cm away from the slits. The first bright fringe is observed at a distance of 2.40 mm from the central bright image.
- A monochromatic light of λ = 588 nm is allowed to fall on the half silvered glass plate G
_{1}, in the Michelson interferometer. If mirror M_{1}is moved through 0.233 mm, how many fringes will be observed to shift? - Blue light of wavelength 480 nm illuminates a diffraction grating. The second order image is formed at an angle of 30
^{∘}from the central image. How many lines in a centimeter of the grating have been ruled? - X-rays of wavelength 0.150 nm are observed to undergo a first order reflection at a Bragg angle of 13.3
^{0}from a quartz (SiO2) crystal. What is the interplanar spacing of the reflecting planes in the crystal? - A converging lens of focal length 5.0 cm is used as a magnifying glass. If the near point of the observer is 25 cm and the lens is held close to the eye, calculate: a) the distance of the object from the lens. b) the angular magnification. What is the angular magnification when the final image is formed at infinity?
- A telescope objective has focal length 96 cm and diameter 12 cm. Calculate the focal length and minimum diameter of a simple eye piece lens for use with the telescope, if the linear magnification required is 24 times and all the light transmitted by the objective from a distant point on the telescope axis is to fall on the eye piece.
- A point object is placed on the axis of and 3.6 cm from a thin convex lens of focal length 3.0 cm. A second thin convex lens of focal length 16.0 cm is placed coaxial with the first and 26.0 cm from it on the side away from the object. Find the position of the final image produced by the two lenses.
- A compound microscope has lenses of focal length 1.0 cm and 3.0 cm. An object is placed 1.2 cm from the object lens. If a virtual image is formed 25 cm from the eye. Calculate the separation of the lenses and the magnification of the instrument.
- Sodium light of wavelength 589 nm is used to view an object under a microscope. If the aperture of the objective is 0.90 cm, a) find the limiting angle of resolution. b) using visible light of any wavelength. What is the maximum limit of resolution for this microscope?

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