Unpolarised light converts to partially or plane polarised  light by many processes. which of the following does not do that?

(1) Double refraction
(2) Scattering
(3) Reflection
(4) Diffraction.

The magnification of an object placed in front of a convex lens of focal length 20 cm is is +2. To obtain a magnification of -2, The object has to be moved a distance equal to:

1) 10 cm
2) 20 cm
3) 30 cm
4) 40 cm

Satellite is moving around the Earth in a circular orbit with a velocity V. If the gravitational force of the Earth were to suddenly disappear, then the satellite would
 
 1) move with a velocity V, tangentially to its circular orbit.
 2) fall towards the surface of the Earth.
 3) move radially outwards with a velocity V.
 4) spirally move away from the Earth.

A body of mass M just starts sliding down an inclined plane ( rough) with inclination θ. such that tanθ=1/3. The force acting on body down the plane in this position is

1) Mg
2) Mg/3
3) (2/3)Mg
4) Mg/√10

A ball of mass 0.2 kg is thrown vertically upwards by applying a force by hand. If the hand moves 0.2 m which applying the force and the ball goes upto 2 m height further, find the magnitude of the force. Consider g = 10 m/s²

1) 22 N
2) 4 N
3) 16 N
4) 20 N

The number of photo electrons emitted for light of a frequency v (higher than the threshold frequency v0) is proportional to :

1) Frequency of light (v)
2) $$v-v_0$$
3) $$Threshold\;frequency\;(v_0)$$
4) Intensity of light

 A pendulum having a period of oscillation of 2 seconds is taken on a planet where g is four times that on the earth. The period of the pendulum would be

1) 4 s

2) 2 s

3) 1 s

4) ½ s

A transverse wave propagating on the string can be described by the equation  y=2sin(10x+300t)..  where x  and  y  are in metres and  tt  in second. If the vibrating string has linear density of  0.6×10⁻³g/cm  then the tension in the string is

1) 5.4N
2) 0.054N
3) 54N
4) 0.0054N

The radius of the Earth is 4 times that of the moon and its mass is 80 times that of the moon. If the acceleration due to gravity on the surface of the earth is 10 m/s², then the acceleration on the surface of the moon will be:

1) 0.98 m/s²
2) 1.47 m/s²
3) 1.96 m/s²
4) 0.49 m/s²

 An isolated conductor will become polarized (in terms of charge) when:

(1) it is touched by a charged object.

(2) it is warmed.

(3) it is brought close to (but not touching) a charged object.

(4) it is charged with a power supply