4.SUBJECT TEST-1-PHYSICS
SUBJECT TEST 1
SUBJECT TEST (PHYSICS)
GENERAL INSTRUCTIONS
SECTION - I
Straight Objective Type
This section contains 12 Single choice questions. Each question has 4 choices (A), (B), (C) and (D), out of which ONLY ONE is correct.
1. A particle when projected in vertical plane moves along the fixed smooth surface with initial velocity 20 m/s at an angle of 60ยบ, so that its normal reaction on the surface remains zero throughout the motion. Then the slope of the tangent to the surface at height 5 m from the point of projection A will be:
(A) 30ยบ (B) 45ยบ
(C) tan1 2 (D) tan1
2. A large open tank has two small holes in its vertical wall as shown in figure. One is a square hole of side 'L' at a depth '4y' from the top and the other is a circular hole of radius 'R' at a depth ‘y’ from the top. When the tank is completely filled with water, the quantities of water flowing out per second
from both holes are the same. Then, 'R' is equal to :
(A) (B) 2L
(C)
L
. L (D) 2
3. A long capillary tube of mass '' gm, radius 2mm and negligible thickness, is partially immersed in a liquid of surface tension 0.1 N/m. Take angle of contact zero and neglect buoyant force of liquid. The force required to hold the tube
vertically, will be - (g = 10 m/s2)
(A) 10.4 mN (B) 10.8 mN
(C) 0.8 mN (D) 4.8 mN
4. A particle executes SHM in a straight line. In the first second starting from rest it travels a distance a and in the next second a distance b in the same direction. The amplitude of S.H.M will be
2a 2
(A)
3a b
(B) a b
(C) 2a b (C) a / b
5. A wall is moving with constant velocity u towards a fixed source of sound of frequency 'f'. The velocity of sound is 'v'. The wavelength of the sound reflected
by the wall is -
(A) v f
v u
(B) f
(C) (C)
v u
(D) (D)
v u . v
f v u f
6. A nonuniform sphere at rest on a rough horizontal surface is acted upon by a force F as shown. The friction force acting on it is
(1) towards left (2) towards right (3) zero
(A) 1 or 2 (B) 1 or 3
(C) 2 or 3 (D) 1or 2 or 3
7. AOB is a swing suspended from vertical poles AA´ and BB´ as shown. If ropes AO and OB of length l 1 and l 2 respectively are massless and are perpendicular to each other with a point mass m hanging from O, the time period of the swing for small oscillations perpendicular to the plane of paper is:
2
F
/////////////////////
(A) (B) 2
(C) 2 (D) 2
8. A particle is executing SHM according to the equation x = A cos t. Average speed of the particle during the
interval 0 t 6 .
(A)
2
3A
(B)
4
3A
(C)
(D)
2 3
9. An equilateral triangular frame is made of three thin massless rods. Three point
masses of mass 'm' each are fixed at vertices of frame as shown. The system is
rotated with uniform angular speed about an (fixed) axis passing through A and normal to plane of triangular frame. Neglect the effect of gravity. The tension in rod connecting mass B and C is -
(A) m 2๐ (B)
m2๐
2 B C
(C)
2
(D) zero
10. Mass m shown in figure is in equilibrium. If it is displaced further by x and released find its acceleration just after it is released. Take pulleys to be light & smooth and strings light.
(A)
4kx 5m
(B)
2kx 5m
(C) 4kx
m
(D) none of these
11. Consider a boy on a trolley who throws a ball with speed 20 m/s at an angle 37° with respect to trolley in direction of motion of trolley which moves horizontally with speed 10 m/s then what will be distance travelled by ball parallel to road :
(A) 20.2 m (B) 12 m
(C) 31.2 m (D) 62.4 m
12. One mole of an ideal gas at pressure P0 and temperature T0 is expanded isothermally to twice its volume and then compressed at constant pressure to (V0/2) and the gas is brought back to original state by a process in which P V (Pressure is directly proportional to volume). The correct representation of process is -
(A) (B)
(C) (D)
SECTION - II
Multiple Correct Answers Type
This section contains 6 Multiple choice questions. Each question has 4 choices (A), (B), (C) and (D), out of which ONE OR MORE may be correct.
13. Heat is supplied to a certain homogeneous sample of matter at a uniform rate. Its temperature is plotted against time as shown in the figure. Which of the following conclusions can be drawn?
(A) its specific heat capacity is greater in the solid state than in the liquid state.
(B) its specific heat capacity is greater in the liquid state than in the solid state.
(C) its latent heat of vaporization is greater than its latent heat of fusion.
(D) its latent heat of vaporization is smaller than its latent heat of fusion.
14. A closed vessel contains a mixture of two diatomic gases A and B. Molar mass of A is 16 times that of B and mass of gas A, contained in the vessel is 2 times that of B. :
(A) Average kinetic energy per molecule of gas A is equal to that of gas B.
(B) Root mean square value of translational velocity of gas B is four times that of A.
(C) Pressure exerted by gas B is eight times of that exerted by gas A.
(D) Number of molecules of gas B in the cylinder is eight times that of gas A.
15. A partition divides a container having insulated walls into two compartments and . The same gas fills the two compartments whose
initial parameters are given. The partition is a conducting wall which can move freely without friction. Which of the following statements is/are correct, with reference to the final equilibrium position?
3V
(A) The Pressure in the two compartments are equal. (B) Volume of compartment is 5
12V
(C) Volume of compartment is 5
(D) Final pressure in compartment is 5P
3
16. In a resonance tube experiment, a closed organ pipe of length 120 cm resonates when tuned with a tuning fork of frequency 340 Hz. If water is poured in the pipe then (given vair = 340 m/sec.) :
(A) minimum length of water column to have the resonance is 45 cm.
(B) the distance between two succesive nodes is 50 cm.
(C) the maximum length of water column to create the resonance is 95 cm.
(D) none of these.
17. A block of mass 2 kg is hanging over a smooth and light pulley through a light string. The other end of the string is pulled by a constant force F = 40 N. The kinetic energy of the particle increase 40 J in a given interval of time. Then :
(g = 10 m/s2)
(A) tension in the string is 40 N
(B) displacement of the block in the given interval of time is 2 m
(C) work done by gravity is – 20 J
(D) work done by tension is 80 J
18. A wire, under tension between two fixed points A and B, executes transverse vibrations in 2nd harmonium. Then :
(A) All points of wire between A and B are in the same phase
(B) All points between A and O are in the same phase
(C) A point between A and O and a point between O and B may have a phase difference of /2
(D) A point between A and O and a point between O and B may have a phase difference of
SECTION - III
Reasoning Type
This section contains 8 Reasoning type questions. Each question has 4 choices (A), (B), (C) and (D), out of which ONLY ONE is correct.
19. Statement-1 : A thin uniform rod is undergoing fixed axis rotation about one of its ends with variable angular acceleration. Then acceleration vector of any two moving points on the rod can not be parallel at an instant of time.
Statement-2 : For a rod undergoing fixed axis rotation, the velocity of any two moving points on the rod at different distances from centre of rotation are different.
(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1
(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1
(C) Statement-1 is True, Statement-2 is False
(D) Statement-1 is False, Statement-2 is True.
20. Statement-1 : A rigid disc rolls without slipping on a fixed rough horizontal surface with uniform angular velocity. Then the acceleration of lowest point on the disc is zero.
Statement-2 : For a rigid disc rolling without slipping on a fixed rough horizontal surface, the velocity of the lowest point on the disc is always zero.
(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1
(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1
(C) Statement-1 is True, Statement-2 is False
(D) Statement-1 is False, Statement-2 is True.
21. Statement-1 : Two stones are simultaneously projected from level ground from same point with same speeds but different angles with horizontal. Both stones move in same vertical plane. Then the two stones may collide in mid air.
Statement-2 : For two stones projected simultaneously from same point with same speed at different angles with horizontal, their trajectories may intersect at some point.
(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1.
(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1
(C) Statement-1 is True, Statement-2 is False
(D) Statement-1 is False, Statement-2 is True
22. Statement-1 : In a perfectly inelastic collision between two spheres, velocity of both spheres just after the collision are not always equal.
Statement-2 : For two spheres undergoing collision, component of velocities of both spheres along line of impact just after the collision will be equal if the collision is perfectly inelastic. The component of velocity of each sphere perpendicular to line of impact remains unchanged due to the impact.
(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1.
(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1
(C) Statement-1 is True, Statement-2 is False
(D) Statement-1 is False, Statement-2 is True
23. Statement–1 : Dimensional analysis can give you the numerical value of constants of proportionality that may appear in an algebraic expression.
Statement–2 : Dimensional analysis makes use of the fact that dimensions can be treated as algebraic quantities.
(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1
(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1
(C) Statement-1 is True, Statement-2 is False
(D) Statement-1 is False, Statement-2 is True.
24. Statement-1 : It is possible for both the pressure and volume of a monoatomic ideal gas of a given amount to change simultaneously without causing the internal energy of the gas to change.
Statement-2 : The internal energy of an ideal gas of a given amount remains constant if temperature does not change. It is possible to have a process in which pressure and volume are changed such that temperature remains constant.
(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1.
(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1
(C) Statement-1 is True, Statement-2 is False
(D) Statement-1 is False, Statement-2 is True
25. Statement-1 : When a wave enters from one medium to another, its frequency does not change.
Statement-2 : Speed of a wave in a medium is property of the source.
(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1
(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1
(C) Statement-1 is True, Statement-2 is False
(D) Statement-1 is False, Statement-2 is True.
26. Statement–1 : A tuning fork of constant frequency sends sound waves in air. If temperature of the air increases, then the wavelength of sound wave in air decreases.
Statement–2 : Speed of sound in air increases with increase in temperature of air.
(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1
(B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1
(C) Statement-1 is True, Statement-2 is False
(D) Statement-1 is False, Statement-2 is True.
SECTION - V
Matrix - Match Type
This section contains 3 questions. Each question has four statements (A, B, C and D) given in Column-I and four or five statements (p,q,r, s or p,q,r, s,t) in Column-II. Any given statement in Column-I can have correct matching with ONE OR MORE statement(s) in Column-II. The answers to these questions have to be appropriately marked as illustrated in the following example. If the correct matches are A-p, A-r, B-p, B-s, C-r, C-s, D-q and D-t then the answer should be written as : A p,r ; B p, s ; C r, s ; D q, t.
27. Two blocks A and B of mass m and 2m respectively are connected by a massless spring of spring constant
K. This system lies over a smooth horizontal surface. At t = 0 the block A has velocity u towards right as shown while the speed of block B is zero, and the length of spring is equal to its natural length at that instant. In each situation of column I, certain statements are given and corresponding results are given in column II. Match the statements in column corresponding results in column and indicate your answer by darkening appropriate bubbles in the 4 × 4 matrix given in the OMR.
Column I Column II
(A) The velocity of block A (p) can never be zero
(B) The velocity of block B (q) may be zero at certain instants of time
(C) The kinetic energy of system of two blocks (r) is minimum at maximum compression of spring
(D) The potential energy of spring (s) is maximum at maximum extension of spring
28. Consider a system of particles (it may be rigid or non rigid). In the column- some condition on force and torque is given. Column- contains the effects on the system. (Letters have usual meaning)
Column-I Column-II
→
(A) Fres 0
→
(p) Psystem will be constant
→
(B) res 0
(q) Lsystem
will be constant
(C) External force is absent (r) total work done by all forces will be zero
(D) No nonconservative force acts. (s) total mechanical energy will be constant.
(t) electric field is zero at same point except at the centre
29. A particle of mass m = 1 kg executes SHM about mean position O with angular frequency = 1.0 rad/s and total energy 2J. x is positive if measured towards right from O. At t = 0, particle is at O and moves towards right. Match the condition in column-I with the position of the particle in column-II and indicate your answer by darkening appropriate bubbles in the 4 × 4 matrix given in the OMR.
Column-I Column-II
(A) speed of particle is 2 m/s at (p) x = + 1m
(B) Kinetic energy of the particle is 1J at (q) x = – 1m
(C) At t = /6 sec. particle is at (r) x = + m
(D) Kinetic energy is 1.5 J at (s) x = – 2 m
30. An ideal monoatomic gas undergoes different types of processes which are described in column-I. Match the corresponding effects in column-II. The letters have usual meaning.
Column-I Column-II
(A) P = 2V2 (p) If volume increases then temperature will also increase.
(B) PV2 = constant (q) If volume increases then temperature will decrease.
(C) C = CV + 2R (r) For expansion, heat will have to be supplied to the gas.
(D) C = CV – 2R (s) If temperature increases then work done by gas is positive.
(t) If volume increases, pressure will also increase.
ANSWER KEY TO SUBJECT TEST-1 (PHYSICS)
1. (D) 2 (C) 3 (B) 4 (A) 5. (D)
6. (D) 7. (D) 8. (D) 9. (D) 10 (C)
11. (D) 12. (C) 13. (A, C) 14. (A,B,C,D) 15. (A,B,C,D)
16. (A, B, C) 17. (A, B, D) 18. (B, D) 19. (D) 20. (D)
21. (D) 22. (A) 23. (D) 24. (A) 25 (C)
26 (D) 27. (A) p (B) q (C) p,r (D) q,s
28 (A) p, t (B) q (C) p,q (D) s 29. (A) r,s (B) r, s (C) p (D) p,q,t
30. (A) p,r,s,t (B) q (C) p,r,s (D) q,r
SUBJECT TEST
GENERAL INSTRUCTIONS
SECTION - I
Straight Objective Type
This section contains 10 Single choice questions. Each question has 4 choices (A), (B), (C) and (D), out of which ONLY ONE is correct.
1. When a hole is made in the side of a container holding water, water flows out and follows a parabolic trajectory. If a hole is made in the side of the container and the container is dropped in free fall ( just before the water starts coming out), the water flow (Neglect effect of surface tension)
(A) diminishes. (B) stops altogether.
(C) goes out in a straight line. (D) curves upward.
2. A small ball of mass m is dropped from an aeroplane moving at 50 m height above the ground with a speed of
25 2 meter/sec. If half of the mechanical energy of ball with respect to ground is lost as a thermal energy due to air friction. The change in the temperature of the ball as it lands on the ground is. Specific heat capacity of ball is 56.25 J/kg. (g = 10 m/sec2)
(A) 5°C (B) 10°C
(C) 20°C (D) 30°C
3. A pendulum of length L and bob of mass M has a spring of force constant k connected horizontally to it at a distance h below its point of suspension. The rod is in equilibrium in vertical position. The rod of length L used for vertical suspension is rigid and massless. The frequency of vibration of the system for small values of is :
(A) (B)
(C) 2
(D)
4. A loop of a string of mass per unit length and radius R is rotated about an axis passing through centre perpendicular to the plane with an angular velocity . A small disturbance is created in the loop having the same sense of rotation. The linear speed of the disturbance for a stationary observer is :
(A) R (B) 2R
(C) 3R (D) zero
5. 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 vector before collision is → and coefficient of
restitution of each collision is 'e', then the velocity of ball after its second collision at B is -
(A) 2 → (B) e →
(C) →
(D) data insufficient
ev
6. Two discs A and B of radii 'R' and '2R' respectively are placed on a horizontal surface as shown. Keeping the disc A motionless, disc B is rotated around it without slippage. When the disc B returns to its starting position, the angle by that it has turned is equal to :
(A) 3 radians (B) 4 radians
(C) 6 radians (D) 8 radians.
7. A curve is plotted to represent the dependence of the ratio of the received frequency to the frequency
emitted by the source on the ratio of the speed of observer Vob to the speed of sound Vsound in a situation in which an observer is moving towards a stationary sound source. The curve is best represented by :
f/f0
2
(A) (B) 1
0
Vob/Vsound
(C) (D)
8. A standing wave pattern is formed on a string. One of the waves is given by equation
y = a cos t – kx + 3) then the equation of the other wave such that at x = 0 a node is formed.
(A) y2
= a sin (t kx +
3
) (B) y2
= a cos (t kx + )
3
(C) y2
= a cos (t kx + 2 ) (D) y
3 2
= a cos (t kx + 4 )
3
9. In the figure the variation of components of acceleration of a particle of mass 1 kg is shown w.r.t. time.
The initial velocity of the particle is → (3 หi 4หj) m/s. The total work done by the resultant force on the particle in time interval from t = 0 to t = 4 seconds is :
(A) 22.5 J (B) 10 J
(C) 0 (D) None of these
10. Two forces F1 and F2 act on a thin uniform elastic rod placed in space. Force F1 acts at right end of rod and F2 acts exactly at centre of rod as shown (both forces act parallel to length of the rod).
F2
F1
C
(i) F1 causes extension of rod while F2 causes compression of rod.
(ii) F1 causes extension of rod and F2 also causes extension of rod.
(iii) F1 causes extension of rod while F2 does not change length of rod.
The correct order of True / False in above statements is
(A) T F F (B) F T F
(C) F F T (D) F F F
SECTION - II
Comprehension Type
This section contains 4 Paragraphs. Based upon each paragraph, 3 multiple choice questions have to be answered. Each question has 4 choices (A), (B), (C) and (D), out of which ONLY ONE is correct.
Paragraph for Question Nos. 11 to 13
Figure shows an electrical calorimeter to determine specific heat capacity of an unknown liquid. First of all, the mass of empty calorimeter (a copper container) is measured and suppose it is 'm1'. Then the unknown liquid is poured in it. Now the combined mass of calorimeter + liquid system is measured and let it be 'm2'. So
the mass of liquid is (m – m ). Initially both were at room temperature ( ).
2 1 0
Now a heater is immersed in it for time interval 't'. The voltage drop across the heater is 'V' and current passing through it is ''. Due to heat supplied, the temperature of both the liquid and calorimeter will rise simultaneously. After t sec; heater was switched off, and final temperature is . If there is no heat loss to surroundings
Heat supplied by the heater = Heat absorbed by the liquid + heat absorbed by the calorimeter (V)t = (m – m ) S ( – ) + m S ( – )
The specific heat of the liquid S =
(V) t
f 0
m1SC
๐ (m2 m1 )
calorimeter
Figure 1
time (t) Figure 2
Temperature vs time graph assuming no heat losses to surrounding.
Radiation correction : There can be heat loss to environment. To compensate this loss, a correction is introduced.
Let the heater was on for t sec, and then it is switched off. Now the temperature of the mixture falls due to heat loss to environment. The temperature of the mixture is measured at t/2 sec. after switching off. Let the fall in temperature during this time is
Now the corrected final temperature is taken as
= +
11. In this experiment voltage across the heater is 100.0 V and current is 10.0A, and heater was switched on for
t = 700.0 sec. Initially all elements were at room temperature = 10.0°C and final temperature was measured
as = 73.0°C. Mass of empty calorimeter was 1.0 kg and the combined mass of calorimeter + liquid is 3.0 kg
. The specific heat capacity of the calorimeter Sc
= 3.0 × 103 J/kg°C. The fall in temperature 350 second after
switching off the heater was 7.0°C. Find the specific heat capacity of the unknown liquid in proper significant figures.
(A) 3.5 × 103 J/kg°C (B) 3.50 × 103 J/kg°C
(C) 4.0 × 103 J/kg°C (D) 3.500 × 103 J/kg°C
12. If mass and specific heat capacity of calorimeter is negligible, what would be maximum permissible error in S . Use the data mentioned below.
m 0, S
0, m
= 1.00 kg, V = 10.0 V, = 10.0 A, t = 1.00 × 102 sec.,
= 15°C, Corrected = 65°C
(A) 4% (B) 5%
(C) 8% (D) 12%
13. If the system were loosing heat according to Newton's cooling law, the temperature of the mixture would change with time according to (while heater was on)
(A) (B)
t t
(C) (D)
t t
Paragraph for Question Nos. 14 to 16
A sinusoidal wave is propagating in negative x–direction in a string stretched along x-axis. A particle of string at x = 2m is found at its mean position and it is moving in positive y direction at t = 1 sec. The amplitude of the wave, the wavelength and the angular frequency of the wave are 0.1meter, /4 meter and 4 rad/sec respectively.
14. The equation of the wave is
(A) y = 0.1 sin (4t –1)+ 8(x – 2)) (B) y = 0.1 sin (t–1)– (x – 2))
(C) y = 0.1 sin (4t –1)–8(x – 2)) (D) none of these
15. The speed of particle at x = 2 m and t = 1sec is -
(A) 0.2 m/s (B) 0.6 m/s
(C) 0.4 m/s (D) 0
16. The instantaneous power transfer through x=2 m and t= 1.125 sec, is -
4
(A) 10 J/s (B) 3 J/s
2
(C) 3 J/s (D) 0
Paragraph for Question Nos. 17 to 19
A block of mass 15 kg is placed over a frictionless horizontal surface. Another block of mass 10 kg is placed over it, that is connected with a light string passing
over two pulleys fastened to the 15 kg block. A force F =
80 N is applied horizontally to the free end of the string. Friction coefficient between two blocks is 0.6. The portion of the string between 10 kg block and the upper pulley is horizontal. Pulley, string &
connecting rods are massless. (Take g = 10 m/s2)
17. The magnitude of accelerations of the 10 kg,15 kg block are :
(A) 3.2 m/s2 , 3.2 m/s2 (B) 2.0 m/s2 , 4.2 m/s2
(C) 1.6 m/s2 ,16/3 m/s2 (D) 0.8 m/s2 , 2.0 m/s2
18. If applied force F = 120 N, then magnitude of acceleration of 15 kg block will be :
(A) 8 m/s2 (B) 4 m/s2
(C) 3.2 m/s2 (D) 4.8 m/s2
19. Continuing with the situation, if the force F = 80 N is directed vertically as shown in the given figure, the accelerations of the 10 kg, 15 kg block will be :
(A) 2 m/s2 towards right and 4/3 m/s2 towards left
(B) 2 m/s2 towards left and 16/5 m/s2 towards right
(C) 6 m/s2 towards left and 4 m/s2 towards right
(D) 16/5 m/s2 towards right and 2/3 m/s2 towards right
F = 80 N
Paragraph for Question Nos. 20 to 22
A horizontal uniform rod of mass 'm' has its left end hinged to the fixed incline plane, while its right end rests on the top of a uniform cylinder of mass 'm' which in turn is at rest on the fixed inclined plane as shown. The coefficient of friction between the cylinder and rod, and between the cylinder and inclined plane, is sufficient to keep the cylinder at rest.
20. The magnitude of normal reaction exerted by the rod on the cylinder is
(A) mg
4
mg
(B) 3
(C) mg
2
2mg
(D) 3
21. The ratio of magnitude of frictional force on the cylinder due to the rod and the magnitude of frictional force on the cylinder due to the inclined plane is:
(A) 1 : 1 (B) 2 :
(C) 2 : 1 (D) 1
22. The magnitude of normal reaction exerted by the inclined plane on the cylinder is:
(A) mg (B)
3 mg
2
(C) 2mg (D) 5mg
4
SECTION - III
Subjective Type
This section contains 4 Short Subjective Questions.
23. Two moles of a monatomic gas in state ‘A’ having pressure P0, and temperature 3T0 is taken to a state B having pressure 3P0 and temperature T0/3 by the process of equation P2T = constant. Then state B is taken to state C keeping volume constant and come back to initial state ‘A’ keeping temperature constant.
(i) Plot a P and T graph. (P on y-axis and T on x-axis)
(ii) Find net work done and heat supplied to gas during the complete cycle.
24. A particle is projected at an angle 60ยบ with speed 10 3, from the point ' A' as shown in the fig. At the same time the wedge is made to move with speed
10 towards right as shown in the figure. Then the time (in seconds) after
which particle will strike the wedge is :
25. B is a source of sound of frequency 300 Hz. A and B collide head on. If the co-efficient of restitution is 1/2 and velocity of sound in air is 330 m/s, find the ratio of frequency appearing to A before collision and after collision.
26. For the arrangement shown in the figure, find the time interval in seconds after which the water jet ceases to cross the wall.
Area of the cross section of the tank A= m2 and area of the
orifice a = 4 cm2. [Assume that the container remaining fixed]
SECTION - IV
Subjective Type
This section contains 4 Long Subjective questions.
27. A particle moving on a smooth horizontal surface strikes a stationary wall. The angle of strike is equal to the angle of rebound & is equal to 37° and the coefficient
of restitution with wall is e = 1 . Find the friction coefficient between wall and the
X
particle in the form 10 and fill value of X.
28. A spool of mass M = 3 kg and radius R = 20 cm has an axle of radius r = 10 cm
around which a string is wrapped. The moment of inertia about an axis perpendicular R
MR2
to the plane of the spool and passing through the centre is
2
. Coefficient of r
friction between the surface and the spool is 0.4. Find maximum value of the M T
tension T (in N) that can be applied so that the spool rolls without
slipping. [Take g = 10 m/s2.]
29. In a tank of horizontal cross-sectional area 1m2, a spring with force constant 2000 Nm–1 is fixed in vertical position upto the height of the water as shown in figure 1. A block of mass 180 kg is gently placed over the spring and it attains the equilibrium position as shown in figure 2. If base area of the block is 0.2m2 and height 60 cm, then find
compression in the spring in cm in equilibrium position. (take g = 10 m/s2;
= 1000 kg/m3)
(Fig.1)
(Fig. 2)
30. A planet revolves about the sun in elliptical orbit of semimajor axis 2 × 1012 m. The areal velocity of the planet when it is nearest to the sun is 4.4 × 1016 m2/s. The least distance between planet and the sun is
1.8 × 1012 m. Find the minimum speed of the planet in km/s.
ANSWER KEY TO SUBJECT TEST-2 (PHYSICS)
1. (B) 2 (B) 3 (D) 4 (B) 5. (C) 6. (A) 7. (A)
8. (D) 9 (B) 10. (C) 11. (A) 12. (C) 13. (C) 14. (A)
15. (C) 16. (D) 17. (A) 18. (B) 19. (A) 20 (C) 21 (A)
22 (D)
23 (i) (ii) Wnet = RT0 (18 ๐n3 – 8), Qnet = RT0 (18๐n3 – 8)
1105
24. 2 sec 25. 961
26. 1000
27. 5 28. 18 29. 40 30. 40
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