To which part of the electromagnetic spectrum does a wave of frequency 5 × 10¹⁹ Hz belong?

Using the concept of force between two infinitely long parallel current carrying conductors, define one ampere of current?

Two equal balls having equal positive charge ‘q’ coulombs are suspended by two insulating strings of equal length. What would be the effect on the force when a plastic sheet is inserted between the two?

Define intensity of radiation on the basis of photon picture of light. Write its S.I. unit.

The electric current flowing in a wire in the direction from B to A is decreasing. Find out the direction of the induced current in the metallic loop kept above the wire as shown.