Askiitians Physics Test209

8/6/2019 Askiitians Physics Test209

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AskIITiansIIT JEE Physics Test

Code AP209

Time - One hour

Please read the instructions carefully. You are allotted 5 minutes specifically for this purpose.

A. General :1. This booklet is your Question paper containing 69 questions.2. Blank papers, clipboard, log tables, slide rules, calculators, cellular phones, pagers and electronic gadgets in

any form are not allowed to be carried inside the examination hall.3. The answer sheet, a machine-readable Objective Response Sheet (ORS), is provided separately.B. Filling the ORS :4. On the lower part of the ORS, write in ink, your name, your Registration No. Do not write these anywhere

else.5. Make sure the CODE on the ORS is the same as that on this booklet and put your signature on the ORS

affirming that you have verified.6. Write your Registration No. in ink, provided in the lower part of the ORS and darken the appropriate bubble

UNDER each digit of your Registration No. with a good quality HB pencil.C. Question paper format.7. The question paper consists of 3 parts (Physics, Chemistry and Mathematics). Each part has 4 sections.8. Section I contains 6 multiple choice question. Each question has four choices (A), (B), (C) and (D), out of

which only one is correct.9. Section II contains 4 questions. Each question has four choices (A), (B), (C) and (D), out of which one or

more choices is correct.10. Section III contains 4 questions. Each question contains Statement -1 (Assertion) and Statement -2

(Reason).Bubble (A) if both the statements are TRUE and STATEMENT-2 is the correct explanation ofSTATEMENT-1.

Bubble (B) if both the statements are TRUE butSTATEMENT-2 is NOT the correct explanation ofSTATEMENT-2.Bubble (C) if STATEMENT-1 is TRUE and STATEMENT-2 is FALSE.Bubble (D) if STATEMENT-1 is FALSE and STATEMENT-2 is TRUE.

11. Section IV contains 3 paragraphs. Based upon each paragraph, three multiple choice questions have to beanswered. Each question has four choices (A) (B) (C) (D) out of which only one is correct.

D. Marking Scheme.12. For each question in Section I, you will be awarded 3 marks if you have darkened only the bubble

corresponding to the correct answer and zero mark if no bubble is darkened. In all other cases, minus one (1) mark will be awarded.

13. For each question in Section II, you will be awarded 4 marks, if you darken only the bubble corresponding tothe correct answer and zero mark if no bubble is darkened. In all other cases, (1) mark will be awarded.

14. For each question in Section III, you will be awarded 3 marks, if you darken only the bubble correspondingto the correct answer and zero mark if no bubble is darkened. In all other cases, (1) mark will be awarded.

15. For each question in Section IV, you will be awarded 3 marks, if you darken only the bubble corresponding

to the correct answer and zero mark if no bubble is darkened. In all other cases, (

1) will be awarded.

Useful Data

Gas Constant R = 8.314 J K1

mol1

1 Faraday = 96500 Coulomb= 0.0821 Lit atm K

1mol

1 1 calorie = 4.2 Joule

= 1.987 2 Cal K1

mol1

1 Ev = 1.6 101

JAvogadros Number Na = 6.023 1023Plancks constant h = 6.625 10

34J . s


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= 6.625 1027

erg . s

Atomic No: H = 1, D = 1, Li = 3, Na = 11, K = 19, Rb = 37, Cs = 55, F = 9, Ca = 20, He = 20, He = 2, O= 8, Au = 79, Ni = 28, Zn = 30, Cu = 29, CI = 17, Br = 35, Cr = 24,Mn = 25, Fe = 26, S = 16, P = 15, C = 6, N = 7, Ag = 47.

Atomic Masses: He = 4, Mg = 24, C = 12, O = 16, N = 14, P = 31, Br = 80, Cu = 63.5, Fe = 56, Mn = 55, Pb

= 207, Au = 197, Ag = 108, F = 19, H = 1, CI = 35.5, Sn = 118.6, Na = 23, D = 2, Cr = 52,K = 39, Ca = 40, Li = 7, Be = 4, AI = 27, S = 32.


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SECTON I

1. A charge passing through a resistor is varying with time as shown in

figure. The amount of heat generated in time t is best described by

(as a function of time):-5c

2sec

1 sec t

-5c

H H

(a) (b)

t 1 sec t 2 sec

H H

(c) (d)

1 sec 2 sec t 1 sec 2 sec t

2. The values of kinetic energy K and potential energy U are measuredas follows :-

K = 100.0 + 2.0 JU = 200.0 + 1.0 J

Then the percentage error in the measurement of mechanical energyis

(a) 2.5%

(b) 1%

(c) 0.5%


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(d) 1.5%

3. A radioactive nucleus X decays to a stable nucleus Y. Then the graph

of rate of formation of Y against the time t will be

R R

(a) (b)

t t

R R

(c) (d)

t t

o

4. Light of wavelength 4000A is incident at small angle on a prism ofapex angle 4o. The prism has nv = 1.5 and nr = 1.48. The angle of

dispersion produced by the prism in this light is

(a) 0.2o(b) 0.08o(c) 0.192o(d) none of these

5. A particle of charge q and mass m moves in a circle of radius raround an infinitely long time charge of linear charge density + . Then

time period will be:- +

r q


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(a) T = 2 r

(b) T2 = r3

(c) T =

(d) T =

Where k = .

6. Maxwells velocity distribution curve is given for two different

temperatures. For the given curves

N

T2

T1

V

(a) T1 > T2

(b) T1 < T2(c) T1 < T2(d) T1 = T2

SECTION II

1. The voltage applied to an X-ray tube is 18 KV. The maximum mass of

photon emitted by the X-ray tube will be:-(a) 2 1013 kg

(b) 3.2 1036 kg

(c) 3.2 1032 kg

(d) 9.1 1031 kg


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2. AB is an L-shaped obstacle fixed on a horizontal smooth table. A ball

strikes it at A, gets deflected and restrikes it at B. If the velocity vectorbefore collision is and coefficient of restitution of each collision is e,

then the velocity of ball after its second collision at B is

A

O

B

(a) e2

(b) e2

(c) e

(d) Data insufficient.

3. In a Youngs Double slit Experiment; D = 1m, d = 1mm and = 5000

nm. The distance of 100th maxima form the central maxima is:-(a) m

(b) m

(c) m

(d) does not exists

4. If the magnetic field at P can be written as K tan then K is:-

i

P|d|


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(a)

(b)

(c)

(d)

SECTION III

1. Statement 1: A uniform thin rod of length L is hinged about one of itsend and is free to rotate about the hinge without friction. Neglect the

effect of gravity. A force F is applied at a distance x from the hinge on

the rod such that force always is perpendicular to the rod. As the valueof x is increased from zero to L, the component of reaction by hinge onthe rod perpendicular to the length of rod increases.

Statement 2: Under the conditions given in statement 1 as x is

increased from zero to L, the angular acceleration of rod increases.

2. Statement 1: Imagine holding two identical bricks under water. Brick

A is completely submerged just below the surface of water, while BrickB is at a greater depth. The magnitude of force exerted by the person

(on the brick) to hold brick B in place is the same as magnitude of

force exerted by the person (on the brick) to hold brick A in place.

Statement 2: The magnitude of buoyant force on a brick completely

submerged in water is equal to magnitude of weight of water displaced

and does not depend on depth of brick in water.

3. Statement 1: The current density at any point in ohmic resistor is in

direction of electric field at that point.


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Statement 2: A point charge when released form rest in a region

having only electrostatic field always moves along electric lines of

force.

4. Statement 1: In free space, a uniform spherical planet of mass M hasa smooth narrow tunnel along its diameter. This planet and another

superdense small particle of mass M start approaching towards eachother from rest under action of their gravitational forces. When theparticle passes through the centre of the planet, sum of kinetic

energies of both the bodies is maximum.

M

Statement 2: When the resultant of all forces acting on a particle like

object (initially at rest) is constant in direction, the kinetic energy ofparticle keeps on increasing.

SECTION IV

Paragraph

Two bodies A and B of masses 10 kg and 5 kg are placed very slightlyseparated as shown in figure. The coefficients of friction between the floor

and the blocks are s = k = 0.4. Block A is pushed by an external force F.

The value of F can be changed.

When the welding between block A and ground breaks, block A will

start pressing block B and when welding of B also breaks, block B will startpressing the vertical wall


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A B5kg

F

1. If F = 20N, with how much force does block A presses the block B

(a) 10 N

(b) 20 N

(c) 30 N

(d) zero

2. If F = 50 N, the friction force acting between block B and ground will

be

(a) 10 N

(b) 20 N

(c) 30 N

(d) none

3. The force of friction acting on B varies with the applied force F

according to the curve :-

FB FB

(a) (b)

F F

10kg


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FB FB

(c) (d)

F F

Paragraph

A body cools in a surrounding of constant temperature 30oC. Its heat

capacity is 2J/oC. Initial temperature of the body is 40oC. Assume Newtons

Law of cooling is valid. The body cools at 38

o

C in 10 minutes

1. In further 10 minutes, it will cool from 38oC to ?(a) 36oC

(b) 36.4oC

(d) 37oC

(d) 37.5oC

2. The temperature of the body in oC denoted by , the variation ofversus time t is best denoted as

40oC 40oC

(a) (b) 30oC

30oC

t t

40oC 40oC


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(c) (d)30oC

t t

3. When the body temperature has reached 38oC, it is heated again so

that it reaches to 40oC in 10 minutes. The total heat required from a

heater by the body is(a) 3.6J

(b) 0.364J

(c) 8J

(d) 4J

Paragraph

Figure shows a conducting rod of negligible resistance that can slide on

smooth U-shaped rail made of wire of resistance 1 /m. Position of the

conducting rod at t = 0 is shown. A time t dependent magnetic field B = 2t

Tesla is switched on at t = 0.

20cm

|l = 40 cm|

1. The current in the loop at t = 0 due to induced emf is

(a) 0.16A, clockwise


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(b) 0.08A, clockwise

(c) 0.08A, anticlockwise

(d) zero

2. At t = 0, when the magnetic field is switched on, the conducting rod ismoved to the left at constant speed 5cm/s by some external means.

The rod moves perpendicular to the rails. At t= 2s, induced emf hasmagnitude(a) 0.12V

(b) 0.08V(c) 0.04V

(d) 0.02V

3. Following situation of the previous question, the magnitude of the

force required to move the conducting rod at constant speed 5cm/s atthe same instant t = 2s is equal to

(a) 0.16 N(b) 0.12 N

(c) 0.08 N

(d) 0.06 N

Askiitians Physics Test209

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