When a ship floats on water

Sound moves with higher velocity if-

Which one of the following is the correct angle between the incident and reflected rays when a ray of light incident normally on a plane mirror?

Magnetism of a bar magnet can be destroyed if it is

(I) kept in the magnetic meridian.

(II) placed in a direction opposite to that of the Earth's horizontal intensity.

(III) heated to a temperature known as Curie temperature.

Select the correct answer using the code given below.

Capacity of a parallel plate condenser can be doubled by

I. doubling the areas of the plates.

II. doubling the distance of separation between the plates,

III. reducing the distance of separation between the plates to half the original separation.

IV. doubling both the areas of the plates and the di stance of separation between the plates.

Select the correct answer using the code given below