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CH-1 (INTRODUCTION TO PHYSICS)1. Because speed of light is equal to = 299,792,458 m/s. 2. (a) [L3] (b) [L3] (c) Dimensionless

3. No, Yes, We cant measure with any manner 4. Yes, No

5. No 6. Only easily available feature is present.

7. (a) By measuring thickness of 50 paper by vernier callipers (b) by using keplars law.

CH-2 (PHYSICS & MATHEMATICS)1. No 2. No, Yes 3. No 4. Yes, Yes 5. Yes, like current

6. (a) Most proper 7. No, Yes 8. Yes 10. No, Yes

11. 3i 4j,3i 4j- + - , 4i 3j,4i 3j+ - 12. No, still it is not possible because a vector can not be equal to a scalar..13. No 14. Yes, No

CH-3 (REST AND MOTION: KINEMATICS)1. Equally wrong 2. These are equal in magnitude 3. No, we can not compare only magnitude of two vectors.

4. t(s)2

04

20

v(ms )-1

20

5. Motion under gravity 6. At its highest point 7. Particle B 8. No

9. Straight line if aeroplane is going with constant velocity. Parabolic, (real path is useless).10. (a) In motion under gravity it is at highest point. (b) Projected particle in vertical direction under gravity

(c) In uniform circular motion.11. t=t1 v (+), a(+), t=t2v(0)a(), t=t3 v() a(+) 12. Both have equal displacement13. Yes, by changing the direction or applying the break. 14. Speed of light does not depend on reference frame.

CH-4 (THE FORCES)1- Force mg applied on earth by object. 2- Contact force between boy and chair, Contact force

between chair and floor, Gravitational force between earth and boy, Gravitational force between chair and earth.3- Not of any type. It is only mental torcher. 4- Electro magnetic force 5- Yes6- (a) 15 (b) 3.6 (c) 0.36 (d) 0.0367- Contact force of floor & block A, Gravitational force of earth.8- (a) Weight of pulley, contact force of string, contact force of clamp.

(b) Weight of boy, contact force of surface, tension force of string.

(c) Weight of block, Tension force of string.9- Weight, contact force, tension force, weight of trolly & person, contact force between trolly & person & surface,

tension force among person, trolly & person is according to newtons third law.

10- Force Force by which Nature of force Direction

On motor 1- By horse Electro magnetic Forward2- By surface Electro magnetic Upward

3- By surface Electro magnetic Back ward4- By person Electro magnetic Down ward5- By earth Gravitational down ward

ANSWERS - SHORT ANSWER QUESTIONS(HC VERMA - TEXT BOOK)

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On horse 1- By person Electromagnetic Back ward2- By motor Electromagnetic Back ward3- By surface Electromagnetic For ward4- By surface Electromagnetic Up ward5- By earth Gravitational Down ward

On driver 1- By horse Electromagnetic For ward2- By motor Electromagnetic Up ward3- By earth Gravitational Down ward

CH-5 (NEWTON'S LAWS OF MOTION)1- Yes, No 2- Zero, yes 3- Straight line, Rest 4- Yes, Yes5- Inertia of motion 6- Yes 7- Yes

8- (a) 20 kg weight (b) No (c) then reading is 1 21 2

2m mm m

+ 9- No 10- Friction force

11- Due to increase in contact time, injury is less.12- One team will win because of getting more force by floor.13- Buoyancy force 14- No, act on a same object 15- Yes, No16- Yes, We can define it by pseudo force. 17-No, by dropping a coin.

CH-6 (FRICTION)1- Not necessary 2- Due to less normal reaction, friction force is less.3- Zero 4- Due to less coefficient of friction5- No, No 6- Due to less pushing force.7- (a) Less (b) Heavy (c) Due to inertia of rest 8- No9- Due to more normal reaction by contact surface 10- By throwing the bag with the help of newtons third law.11- Due to cold welding

CH-7 (CIRCULAR MOTION)1- Yes, By applying break or turning2- The centrifugal force will dry the cloths for the person sitting on the drum & the centripetal force will dry the clothesfor person who is washing the clothes.

3- By friction force 4- By normal reaction 5- No 6- Due to inertia of rest 7- Outer 8- (B)9- By applying break 10- Tension will be more during oscillation.

CH-8 (WORK AND ENERGY)1- No 2- No3- Yes, work depends on the position of observer.4. Work done by the static friction force on the person travelling in bus w.r.t to observer standing on ground.5- Yes, person moving up in an elevator 6- Yes, internal energy converts into kinetic energy.7- Yes 8- No, No 9- Potential energy is a reference dependent quantity.10- Yes 11- Positive, Negative12- (a) Positive (b) Negative (c) Zero (d) Negative (e) Positive13- Decrease 14- Work done by you converts in it. 15- Velocity can be changed but speed not.

16- (a) Ki = 12

mv02 , (b) Kf = 0, Wk.f. =

12

mv02

17. (a) Ki =0, Kf = 12

+ mv02 (b) +

12

mv02

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CH-9 (CENTRE OF MASS, LINEAR MOMENTUM, COLLISION)1- Yes 2- Yes 3- Yes 4- (a) Yes (b) Yes (c) No 5- No 6- No, Tension force 7- Due to high friction force 8- Yes9- No

10- Yes, Yes, No 11- No, No 12- Yes, No, only magnitude of net momentum can be calculated 13- Yes, less than r2

14- Yes, if not completely closed15- Centre of mass does not shift. 16- Yes17- Possibility of falling of forward person is high. 18- No. 19- Yes 20- No 21- Friction force 22- Ground reaction force

23- In b particle emission, a neutrino particle is also emitted due to this momentum is conserved.

24- Go back side in van. 25- No.CH-10 (ROTATIONAL MECHANICS)

1. No 2. Yes, line perpendicular to the plane of motion of pendulum passing through the suspension point.3. No 4. Yes, Yes 5. No, Yes 6. No 7.No, Yes8. 0.5 mg, yes 9. No 10. No, Yes 11. No12. No 13. No 14. Torque of weight 16. Near to upper end17. Yes, No, Normal shifts 18. End B 19. Yes 20. Duration increases 21. Ring 22. Yes

CH-11 (GRAVITATION)

1- No, No, Yes 2- No 3- FM

Constant 4- No 5- Moon also rotates around the sun.

6- Equal weight 7- Apple 8- 32kr

- 9- Yes, No, we should use 1 2Gm mU 20r

= - +

10- Yes, if we use spring balance. 11- Real weight, No 12- Increases 2%13- No, rotate with satellite, Astronauht should bring the bolt with him. 14- Yes15- No, Yes 16- No 17- 2mg m r> w 18- No, rotating satellite from east to west.19- The neutral point is near the moon and away from earth.

CH-12 (SHM)1- No, because entire routine of the person will not be repeated in exact fasion.2- No 3- Yes, No 4- Amplitude, zero 5- Yes6- Speed will be high on point P .This will not disappoint us.7- It is easy to locate lowest point.9- Yes, Yes 10. (B) 11- It will gain time because time period will decrease12- No 13- Increase then decrease14- Yes 15- Marching frequency comes in resonace with bridge frequency.16- Simple harmonic motion

CH-13 (FLUID MEACHNICS)

1. No, sepration between the molecule may differ 2. P = fA

, Area of the needle is less than the contact area of rod

3. As density of the liquid will be variable 4. Less than the actual difference. No 5. Yes, Yes, No. liquid surface will be

perpendicular to the effective g is = geff = 2g R- wrr 6. Length will be more than 76cm but height will be same that

of 76 cm. 7. No. it can only rise upto a height of 76 cm. 8. Effective g is zero therefore height will be 1m.9. No. as pressure outside the tube is greater than pressure inside the tube 10. Yes, No. 11. Density of sea water isgreater than density of fresh water therefore buyont force is greater. 12. No 13. Rock should removed from the boat.14. Velocity of water increases due to fall in potential energy in result of this area of cross section reduces 15. Due toincrease in the velocity of water stream due to reduction of area. 16. Due to reduction of pressure outside the convasby bernoullis theoram.

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CH-14 (PROPERTIES OF MATTER)1. First decreases upto an extent 2. Librated in form of heat 3. Thicher bones reduces the stress 4. Much less than the1% 5. Absorbed by the rubber sheets 6. Difference in the internal energy of the acid 7. Force due to surface tensionis only acts on the free surface of liquid. 8. Adhesive force decreases. 9. Neither rises nor fall it will remain at samelevel. 10. No. 11. No Adhesive force does not acts on bulge portion to reduce surface energy it will acquire a shapeof sphere. 12. No 14. Due to sticly wings to reduce surface energy 15. Projected force due to pressure is in thedirection of force due to surface tension 16. Yes 17. No. 18. Due to viscous force on the liquid 19. Costor oil due tohigh viscosity.

CH-15 (WAVE MOTION AND WAVES ON A STRING)

1- No 2- Non-mechanical 3- Negative -x 4. Pmax

V 2 A A 1A

V2

p

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CH-23 (HEAT & TEMPERATURE)1.Yes 2. No 3. Yes, because heat is proportional to temperature4. Experiment containing a barometer and a closedd vessel to be heated. 5. No

6. Due to abnormal behavior of water near at 4C. 7. No 8. No 9. No10. The lid will expand due to increasing temperature. 11. Quenching does not take place if water should be putshowly 12. Yes 13. Here volume indicates the volume occupied by the spherical shel l.

CH-24 (KTG)1. Yes, No 2. Due to the gases in form of liquid state 3. No 4. No, No

5. This statement is wrong but macroscopically the temperature is same. 6. Yes 7. No

8. There will be no motion. 9. You can not determine pressure, density and average kinetic energy.

10. Charles law is valid for constant mass.11. Due to increasing pressure, boiling point will increase. 12. More vaporization13. Yes, No 14. Due to increasing vaporization.

CH-25 (CALORIMETRY)1. No 2. This is a fact 3. To isolate the system 4. Yes till flow of energy.5. To increase the contact time and area 6. In changing state 7. (a) Infinite (b) Infinite8. Internal energy of vapour is more 9. Water takes more time to be hot & to cool. 10. Low specific heat.

CH-26 (LAWS OF THERMODYNAMICS)1. No 2. Yes 3. mgh, 0, No] No 4. Fd, No 5. Heat6. No (Mechanical work) 7. No, Yes 8. No, No 9. Yes 10. No

11. Cooling due to adiabatic expansion. 12. Yes, No 13. No14. Temperature of sink will be zero kelvin 15. Yes, No

CH-27 (SPECIFIC HEAT CAPACITIES OF GASES)1. No, No (Infinite) 2. No () 3. No, (zero) 4. CP is slightly greater then CV.5. CP CV

> R 6. Yes, Free expansion in insulating system of ideal gas

8. No, No 9. No 10. f = 2 2 2

1 1.29 1 0.29= =g - - = 6.89 = 6

CH-28 (HEAT TRANSFER)1. Because this is not a continuous process. it has quantum nature.

2. Yes, But it absorbs much. 3. Convection currents, No,No 4. No 5. Wooden chair 6. Yes, Yes

7. Due to forced convection 8. Due to low pressure 9. No 10. Clouds reflect the energy

11. White dress has low absorbing power.

CH-29 (ELECTRIC FIELD AND POTENTIAL)1- No. 2- Yes 3- Yes, Yes 4- No 5- Due to charge generated by friction6- No 8- No 9- No, path will be according to position 10- 1%3 11- No12- The length of dipole w.r.t. distance of observer from centre. 13- Due to free electrons14- No, total charge will zero

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CH-30 (GAUSS'S LAW)1- Maximum when electric field is perpendicular to surface, minimum when parallel.2- Yes, flux i.e. number of electric lines remain same.3- Zero, if conductor is spherical shell then remain unchanged, Yes4- Zero, Yes if shell is conductor then field is zero. 5- No 6- No 7- No, No, No

CH-31 (CAPACITORS)

1. 1 2Q Q2- 2. No 3. Both of them have equal potential 4. 0] 0] The whole positive charge will come on the outer

surface. 5. No, the knowledge of potential is also necessary. 7. AttractionCH-32 (ELECTRIC CURRENT IN COUNDUCTORS)

1. 10W, 45W, 90W 2. Yes ] East to west 3. Yes ] left to right 4. Forward to backward 5. Drift velocity is aaverage quantity. 6. Electric field in cunductor is zero at electro static equilibrium position. If potential is applied theelectric field will be non-zero. 7. No 8. Due to less resistance 9. U i210. No 11. No 12. No, yes 14. Charge 15. Potentiometer16. No 17. Yes

CH-33 (THERMAL AND CHEMICAL EFFECT OF ELECTRICAL CURRENT)1. The resistance will increase due to increase in temperature with time therefore current decreases with time.

2.Yes, 1 2r R R= 3.NoCH-34 (MAGNETIC FIELD)

1. Yes, No 2. Yes, Yes time varying magnetic field exists.3. No, if magnetic field is uniform then only it will be zero.4. Yes, No 5. If it enters tangentially 6.Yes] k 7. Yes, if plane of loop is perpendicular to B

r

8. Magnetic field only exerts force on moving charge i.e. electron. 9. For stable equilibrium q = 010. Rate of change of flux gives emf

CH-35 (MAGNETIC FIELD DUE TO A CURRENT)

1- Vertically upward, vertically downward, due west, due east 2. 0B2m= p

id = 2

0

i2 d cp 0 0

1C = m

3. Going away from osberver 4. No 6. Yes, Yes 7. No 8. Force and torque both work on it.9. The electrostatic force is greater than magnetic force, while electric force on current element is zero.10. Yes 11. Magnetic field of on wire cancel out by another wire. 12. Magnetic force does not work on pointcharge.

CH-38 (ELECTROMAGNETIC INDUCTION S)1. No] Flux f is constant w.r.t time.

2.IT

DD Will be maximum when switch is open because time interval is very less.

3. To prevent the change in flux Eddy currents will be generated in coil which opposes the oscillatory motionof coil.

4. According to Lenzs law, the changing flux exerts force on magnet.5. Yes, When the current in first loop changes till current will induced in second loop. Loop will repel each other.6. Yes, There is a change in current till current will be induced. Loop will attract.7. In the box change in magnetic field is very less.9. Induced eddy current opposes the motion.11. (a) Plane of both loops are parallel. (b) Plane of both loops are perpendicular12. On centre 13. On centre

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CH-39 (ALTERNATING CURRENT )1. Infinite 2. Zero 3. Same 4. Yes 5. Yes, This is according to ohms law6. The rms value of current will increases because Irms = Vwc 7. No 8. No

9. 2 20 0i R i R,2 2

,0, The theory of superposition will obey current while not for heat energy

10. No 11. The impedance will more when applying AC . If we apply DC the transformer will burn becanbe of high current.

12. No, No 13. Decrease, may decrease or may increase 14. Yes, No

CH-42 (PHOTOELECTRIC EFFECT AND WAVE-PARTICLE DUALITY)1. No 2.No 3. (a) c (b) c 4.No, No 5. Number of photons will be decreased if room is maintained ata constant lower temperature. 6. No, energy of a photon cant be called its KE or IE.7. No 8. Green light 9. Every photon should be capable to start photo synthesis10. Metal gains positive charge which stops furthur emission of photoelectrons.11. No 12. (a) proton (b) equal (c) proton 13. No, there is no colour of matter (probale) waves.

CH-43 (BOHRS MODEL AND PHYSICS OF THE ATOM)

1. Infinite, infinite 2. Yes, (13.6) 2

2

Zn

= (13.6) Z=n 3. Lyman Series (Absorption transitions can only occur from

n=1 to n>1) 4. At room temperature, hydrogen atoms is in ground state. 5. Balmer series lies in the visible range ofthe spectrum

6. P.E. + K.E. = T.E. P.E.+ P.E. T.E.2

= |P.E|as K.E.2

= T.E. = P.E.2

-

Potential energy of first state is 27.2eV when infinity is considered at 0 eV therefore if will beat 17.2eV when infinityis considered at 10eV. P.E. + K.E. = T.E. 17.2 + 13.6eV = T.E T.E. = 3.6 eV

7. hv = 13.6 2 21 2

1 1n n

- for limit of by mans series [n1 = 1, n2 = ]

v = constant 1 11

- ...(1) v = constant 1 14

- ...(2)

for limit of balmer series [n1 = 2 ; n2 = ] By subtrating (1) and (2) we get first line of lyman8. Ability to work is energy = qDv, Ionization energy = eU (Ionization potential)For some other unit it will not hold true. 9. Yes 10. Yes, Yes

CH-44 (X-RAYS)1. KE of incident electrons 2. No 3. Yes 4. Yes 5. No 6. No 7. Yes8. Yes 9. No, due to low energy gap between energy levels. 10. X-ray photons are more energetic

CH-46 (THE NUCLEUS)

1. As neutron is an unstable particle 2. Yes, nuclear force is spin dependent3. Nuclear force is a short range force. 4. Carbon, lead5. 24Mg 6. Generation of cathode rays is an atomic phenomenon and generation of b-rays is a nuclear phenom-enon we can differentiate on the basis of their energy.

7. From extrenally supplied energy. 8. Yes 9. 73 Li 10. Yes 11. Lighter, same

12. Electrostatic repulsion prevents their fusion.