Electromagnetic Waves — Physics STD 12 Science — Question

What is the effect on the magnitudes of resistance and resistivity of deforming the shape of a substance?

If a graph is drawn between different potential differences applied across the ends of the conductor and their corresponding values of current, then what type of graph is obtained?

Two charges of magnitudes – 2Q and + Q are located at points (a, 0) and (4a, 0) respectively. What is the electric flux due to these charges through a sphere of radius ‘3a’ with its centre at the origin?

Answer the following question:
When a tiny circular obstacle is placed in the path of light from a distant source, a bright spot is seen at the centre of the shadow of the obstacle. Explain why?

In which directions do the electric and magnetic field vectors oscillate in an electromagnetic wave propagating along the x-axis?

Do two distinct poles actually exist at two nearby points in a magnetic dipole?

Define capacitor reactance. Write its S.I. units.

A gas is kept in a rigid cubical container. If a load of 10kg is put on the top of the container, does the pressure increase?

What are permanent magnets? Give one example.

In a rectangular wire, due to a source of emf, a constant current is flowing from left to right. When the switch of the source is off, then what will be the direction of induced current in the wire?