1 The electric resistance of a certain wire of iron is R. If its length and radius are both doubled, then A) the resistance and the specific resistance, will both remain unchanged B) the resistance will be doubled and the specific resistance will be halved C) the resistance will be halved and the specific resistance will remain unchanged D) the resistance will be halved and the specific resistance will be doubled
2 Two thin lenses are in contact and the focal length of the combination is 80 cm. If the focal length of one lens is 20 cm, then the power of the other lens will be A) 1.66D B) 4.00D C) -100D D) -3.75D
3 A point charge q is rotated along a circle in the electric field generated by another point charge Q The work done by the electric field on the rotating charge in one complete revolution is A) Zero B) Positive C) Negative D) zero if the charge Q is at the centre and non zero otherwise.
4 In a common base mode of a transistor, the collector current is 5.488 mA for an emitter current of 5.60 mA. The value of the base current amplification factor (β) will be A) 49 B) 50 C) 51 D) 48
5 A raindrop of radius 0.3 mm has a terminal velocity in air is 1 m/s. The viscosity of air is 8 x 10-5 poise. The viscous force on it is A) $45.2\times 10^{-4}$dyne B) $101.73\times 10^{-5}$ dyne C) $16.95\times 10^{-4}$ dyne D) $16.95\times 10^{-5}$dyne
6 Consider a pair of insulating blocks with thermal resistances R1 and R2 as shown in the figure. The temperature θ at the boundary between the two blocks is A) $\frac{\theta_{1}\theta_{2}\sqrt{R_{1}R_{2}}}{(\theta_{1}+\theta_{2})(R_{1}+R_{2})}$ B) $\frac{\theta_{1}R_{1}+ \theta_{2}R_{2}}{(R_{1}+R_{2})}$ C) $\frac{\left[\left(\theta_{1}+ \theta_{2}\right) R_{1}R_{2}\right]}{\left(R_1^2+ R_2^2\right)}$ D) $\frac{\left(\theta_{1}R_{2}+ \theta_{2}R_{1}\right)}{R_{1}+ R_{2}}$
7 A solid sphere is rotating in free space. If the radius of the sphere is increased keeping mass the same which one of the following will not be affected? A) Angular velocity B) Angular momentum C) Moment of inertia D) Rotational kinetic energy
8 The Young's modulus of a perfectly rigid body is A) Unity B) Zero C) Infinity D) Some finite non zero constant
9 The figure below shows currents in a part of an electric circuit. The current I is A) 1.7amp B) 3.7amp C) 1.3amp D) 1amp
10 Escape velocity when a body of mass m is thrown vertically from the surface of the earth is v, what will be the escape velocity of another body of mass 4 m is thrown vertically A) v B) 2v C) 4v D) None of these
11 A solid cylinder of mass m and radius R rolls down the inclined plane without slipping. The speed of its C.M. when it reaches the bottom is A) $\sqrt{2gh}$ B) $\sqrt{\frac{4gh}{3}}$ C) $\sqrt{\frac{3}{4gh}}$ D) $\sqrt{4gh}$
12 A liquid is allowed to flow into a tube of truncated cone shape. Identify the correct statement from the following. A) The speed is high at the wider end and low at the narrow end B) The speed is low at the wider end and high at the narrow end. C) The speed is same at both ends in a stream line flow. D) The liquid flows with uniform velocity in the tube
13 The surface of a metal is illuminated with a light of 400 nm. The kinetic energy of the ejected Photoelectrons was found to be 1.68 eV. The work function of the metal is? (hc = 1240eV.nm) A) 3.09 eV B) 1.42 eV C) 1.51eV D) 1.68 eV
14 If the differential equation for a simple harmonic motion is $\frac{d^{2}y}{dt^{2}}+2y = 0$, the time period of the motion is A) $\pi\sqrt{2}$ sec B) $\frac{\sqrt{2s}}{\pi}$ sec C) $\frac{\pi}{\sqrt{2}}$ sec D) $2\pi$ sec
15 The work done by an uniform magnetic field on a moving charge is A) zero because $\overrightarrow{F}$ acts parallel to $\overrightarrow{v}$ B) positive because $\overrightarrow{F}$ acts perpendicular to $\overrightarrow{v}$ C) zero because $\overrightarrow{F}$ acts perpendicular to $\overrightarrow{v}$ D) negative because $\overrightarrow{F}$ acts parallel to $\overrightarrow{v}$
