A ray of light is incident on a medium with the angle of incidence ‘i’ and is refracted into a second medium with the angle of refraction ‘r’. The graph of sin i versus sin r is as shown. Find the ratio of the velocity of light in the first medium to the velocity of light in the second medium.

Define temperature coefficient of resistivity.

Name the electromagnetic waves that are widely used as a diagnostic tool in medicine.

OR

Name the current which can flow even in the absence of electric charge.

Two particles have equal momenta. What is the ratio of their de-Broglie wavelengths?

OR

Monochromatic light of frequency 6.0x 10¹⁴ Hz is produced by a laser. What is the energy of a photon in the light beam?

A network of resistors is connected to a 16 V battery with an internal resistance of 1 Ω as shown in the following figure. Compute the equivalent resistance of the network.

OR

A 9 V battery is connected in series with a resistor. The terminal voltage is found to be 8 V. Current through the circuit is measured as 5 A. What is the internal resistance of the battery?