1 figure shows three-resistor configuration R1, R2 and R3 connected to 3V battery. If the power dissipated by the configuration R1, R2 and R3 is P1, P2 and P3, respectively, then
- P1 >P2 >P3
- P1>P3>P2
- P2>P1>P3
- P3>P2>P1
Ans
P2 > P1 > P3
2. Student I, II and III perform an experiment for measuring the acceleration due to gravity (g) using a simple pendulum. They use different length of the pendulum and/or record time for different number of oscillations. The observation are shown in the table
Least count for length = 0.1cm
Least count for time = 0.1 s
If E1, EII and EIII are the percentage errors in g, i.e., for student I, II and III, respectively,
A. EI is 0
B. EI is minimum
C. EI = EII
D EII is maximum
Ans
3 Which one of the following statement is wrong in the context of X-rays generated from a X-ray tube?
(A) Which one of the following statement is wrong in the context of X-rays generated from a X-ray tube?
(B) Cut-off wavelength of the continuous X-rays depends on the atomic number of the target.
(C) Intensity of the characteristic X-rays depends on the electrical power given to the X-rays tube. (D) Cut-off wavelength of the continuous X-rays depends on the energy of the electrons in the X-ray tube
Ans
Cut off wavelength does not depend on the atomic no of target
4 Two beams of red and violet colours are made to pass separately through a prism (angle of the prism is 60o). In the position of minimum deviation, the angle of refraction will be
(A) 30o for both the colours
(B) greater for the violet colour
(C) greater for the red colour
(D) equal but not 30o for both the colours
Ans
Angle of refraction will be 30o for both the colours in the position of minimum deviation
5 A spherically symmetric gravitational system of particles has a mass density
Where r0 is a constant. A test mass can undergo circular motion under the influence of the gravitational field of particles. Its speed V as a function of distance r(0<r<¥) from the center of the system is represented by
Ans
6 An ideal gas is expanding such that PT2 = constant. The coefficient of volume expansion of the gas is
Ans
7Assume that the nuclear binding energy per nucleon (B/A) versus mass number (A) is as shown in the figure. Use this plot to choose the correct choice (s) fiven bellow.
(A) Fusion of two nuclei with mass numbers lying in the range of 1 < A < 50 will release energy
(B) Fusion of two nuclei with mass numbers lying in range of 51 < A < 100 will release energy
(C) Fission of a nucleus lying in the mass range of 100 < A < 200 will release energy when broken into two equal fragment
(D) Fission of a nucleus lying in the mass range of 200 < A < 260 will release energy when broken into two equal fragment
Ans
(i) if both are between 1 & 50 new nuclear has moss no lying in the range 1 to 100. thus there will be no change in EPN therefore, fusion will not occur.
(ii) if mass no of both lies between51 & 100
=> Nuclear of mass EPN is formed
=> Energy is released
(iii) fission will not occur since EPN decreases
(iv) fission will occur, since EPN increases - energy is released
8 Two balls, having linear momenta  and  , undergo a collision in free space. There is no external force acting on the balls. Let  and  be their final momenta. The following option(s) is(are) NOT ALLOWED for any non-zero value of p, a1, a2, b1, b2, c1, and c2. 
Ans
since c1 is non zero , 
hence correct
(ii)
when c1 = - c2
then 
hence is correct
hence is correct
hence is correct
9 In a young’s double slit experiment, the separation between the two slits is d and the wavelength of the light is l. The intensity of light falling on slit 1 is four times the intensity of light falling on slit 2. Choose the correct choice(s).
(A) If d=l, the screen will contain only one maximum
(B) If l<d<2l, at least one more maximum (besides the central maximum) will be observed on the screen
(C) If the intensity of light falling on slit 1 is reduced so that it becomes equal to that of slit 2, the intensity of the observed dark and bright fringes will increase
(D) If the intensity of light falling on slit w is increased so that it becomes equal to that of slit 1, the intensities of the observed dark and bright fringes will increase
Ans
(i) when d=l, the path difference d sin q will never be equal to l except when q =90o i.e. at the center of the spectrum
=>only 1 maxima will be found
(ii) when l<d<2l the path difference d sin q will be equal to l for 1 more +ve value of q ¹90o at least 3 maxima will be found
=> 1 at centre
=> 2 at +ve, -ve value of obtain
(iii) if intensity is reduced
(iv) of both intensities are now 4I0
=> intensity of bright fringe increases
=> Intensity of dark fringes reduces to zero
hence wrong
10 A particle of mass m and charge q, moving with velocity V enters Region II normal to the boundary as shown in the figure. Region II has a uniform magnetic field B perpendicular to the plane of the paper. The length of the Region II is . Choose the correct choice(s).
(A) The particle enters Region III only if its velocity V>
(B) The particle enters Region III only if its velocity V<
(C) Path length of the particle in Region II is maximum when velocity V=
(D) Time spent in Region II is same for any velocity V as the particle returns to Region I
Ans
F(normal force on m)
(i) (i) true and (ii) false
(ii) of the particle rotates at radius l
distance covered = pr
0£ r £ l => max distance is pl
11 STATEMENT-1: Two cylinders, one hollow (metal) and the other solid (wood) the same mass and identical dimensions are simultaneously allowed to roll without slipping down an inclined plane from the same height. The hollow cylinder will reach the bottom of the inclined plane first.
And
STATEMENT-2: By the principle of conservation of energy, the total kinetic energies of both the cylinders are identical when they reach the bottom of the incline
(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 False
Ans
statement 1 is false
=> a2 > a1
=> solid cylinder reaches earlier
statement II is true
hence d
12 STATEMENT-1: The stream of water flowing at high speed from a garden hose pipe tends to spread like a fountain when held vertically up, but tends to narrow down when held vertically.
And
STATEMENT-2: In any steady flow of an incompressible fluid, the volume flow rate of the fluid 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 False
Ans
statement I is true( by observation)
statement II is also true
but statement II does explain statement I since when water moves up velocity decreases and area increase while when water moves down, velocity increases and thus stream down.
13 STATEMENT-1: In a meter bridge experiment, null point for an unknown resistance is measured. Now, the unknown resistance is put inside an enclosure maintained at a higher temperature. The null point can be obtained at the same point as before by decreasing the value of the standard resistance.
And
STATEMENT-2: Resistance of a metal increases in temperature.
(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 False
Ans
(By increasing g the temperature, the unknown hesitance increases
value of standred resistance has to be increased for the same null points to match
=> statement I is false and statement II is true
14 STATEMENT-1: An astronaut in an orbiting space station above the earth experiences weightlessness.
And
STATEMENT-2: An object moving around the earth under the influence of earth's gravitational force is in a state of 'free-fall'.
(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 False
Ans
Statement I is true & statement II also
Since an object moving around the earth under the earth’s gravitational force is in free fall \astronaut within the space station experiences weight less ness because pseudo force is balanced by gravitational attraction.
This is same as in an object kept in a freely falling lift.
Paragraph for question Nos. 15 to 17
A small block of mass M moves on frictionless surface of an inclined plane, as shown in figure. The angle of the incline suddenly changes from 60o to 30o at point B. The block is initially at rest at A. Assume that collisions between the block and the incline are totally inelastic ( g = 10 m/s2).
15 The speed of the block at point B immediately after it strides the second incline is
Ans
16 The speed of the block at point C, immediately before it leaves the second incline is
Ans
17 If collision between the block and the incline is completely elastic, then the vertical (upward) component of the velocity of the block at point B, immediately after it strikes the second incline is
Ans
if collision is completely elastic
Paragraph for question Nos. 18 to 20
A small spherical monatomic ideal gas bubble g=5/3 is trapped inside a liquid of density r1(see figure). Assume that the bubble does not exchange any heat with the liquid. The bubble contains n moles of gas. The temperature of the gas when-the bubble is at the bottom is T0, the height of the liquid is H and the atmospheric is Po (Neglect surface tension).
Figure:
18 As the bubble moves upwards, besides the buoyancy force the following force are acting on it
(A) Only the force of gravity
(B) The force due to gravity and the force due to the pressure of the liquid
(C) The force due to gravity, the force due to the pressure of the liquid and the force due to viscosity of the liquid.
(D) The force due to gravity and the force due to viscosity of the liquid
Ans
forces acting on the body
=> gravitation force, => F viscosity force, => buoyancy force
force due to pressure is accelerated within buoyancy force.
19 when the gas bubble is at a height y from the bottom, its temperature is
Ans
since no heat is exchanged => adiabatic process
20 The buoyancy force acting on the gas bubble is (Assume R is the universal gas constant)
Ans
buoyancy force = weight of displaced water
Paragraph for question Nos. 21 to 23
In a mixture of H-He+ gas (He+ is singly ionized He atom), H atoms and He+ ions are excited to their respective first excited states. Subsequently, H atoms transfer their total excitation energy to He+ ions (by collision). Assume that the bohr model of atom is exactly valid.
21 The quantum number n of the states in finally populated in He+ ions is
(A) 2 (B) 3 (C) 4 (D) 5
Ans
first excitation energy of H – atom 
energy observed by He+ ion 
=> n2 = 4
22 The wavelength of light emitted in the visible region by He+ ions after collisions with H atoms is
(A) 6.5X10-7 m (B) 5.6X10-7 m (C) 4.8X10-7 m (D) 4.0X10-7 m
Ans
visible region wavelength 4®3 transition
23 The ratio of the kinetic of the n = 2 electron for the H atom to that of He+ ion is
Ans
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