Find the ratio of the intensity at the centre of a bright fringe to the intensity at the point on equarter of the distance between two fringes from the centre.

Mangetic field intensity at the centre of a coil of 50 turns, radius 0.5 m and carrying a current of 2 A is

Find the electric intensity at a point in between two parallel opposite charged infinite sheets.

Show that if at some part of a field the lines of force have the form of arcs of concentric circles whose centres are at point O (Fig.), the field intensity at each point in this part of the field should be inversely proportional to the distance from the point to O.

In a Young's double slit experiment ,light has a frequency of 6 xx 10^(14) s^(-1) .The distance between the centres of adjacent brigth fringes is 0.75 mm. If the screen is 1.5m away then, find the distance between the slits.

Assuming that the earth’s radius is 6400 km and that it subtends an angle of 57’ at the centre of the moon, find the distance of the centre of the moon from the earth’s centre.

How does the angular separation of interfernce fringes change in Young's experiment, if the distance between the slits is increased?

Ratio of intensity of two waves is given by 4:1. Then, ratio of the amplitude of the two waves is: