Physics Test - 57

Energy is continuously generated in the sun due to Nuclear fusion.

A microwave is the fastest communication channel whereas Optical fiber is a way of transferring data not a way of communication.

A convex mirror is used to form an image of a real object. The imageis diminished in size/is erect/always lies between the pole and the focus.

As the frequency of sound is higher, women have shriller voices than men.

The shrillness or pitch of a sound is determined by its frequency. The higher the pitch shriller the voice. As the sounds produced by vocal cords of women are higher than men so women have shriller voices than men. Because their vocal cord is of smaller size. As their vocal cord is more stretched than men's.

The submerged portion of the ice on melting shrinks a little in volume. so the level of water goes down a little. But this is just made up by the water added by the melting of upper portion. Addition is equal to the Shrinkage. Hence level is unchanged.

The rotational effect of a force on a body about an axis of rotation is described in terms of moment of force.

Two bodies A and B are of same mass and same amount of heat is given to both of them. If the temperature of A increases more than that of B because of heat addition, thenthe specific heat capacity of A is less than that of B.

In a Cinema hall, the distance between the projector and the screen is increased by 2%. Then the intensity of illumination on the screen is decreased by 4%.

Water has maximum density at 4 C.

To evaporate the water that oozes out, heat is required. Part of this heat is taken from the water inside which therefore become cool. Therefore (C) is correct. Here evaporation is less, so cooling too is less.