The period of oscillation of 3 cm microwaves is 1 × 10¹⁰ (Physics, Volume 1, by Halliday). The period of oscillation is the smallest interval of time in which a system undergoing oscillation returns to the state it was in at the beginning of the oscillation.

Correct Option: B

The period of oscillation of 3 cm microwaves is 1 × 10¹⁰ (Physics, Volume 1, by Halliday). The period of oscillation is the smallest interval of time in which a system undergoing oscillation returns to the state it was in at the beginning of the oscillation.

When the angle of incidence is greater than the critical angle, no refraction occurs. Instead, the incident beam is reflected, obeying the Law of Reflection. This is called Total internal reflection. In the formation of a rainbow, Total Internal Reflection occurs at the rear of the raindrop - the water-to-air interface.

Correct Option: C

When the angle of incidence is greater than the critical angle, no refraction occurs. Instead, the incident beam is reflected, obeying the Law of Reflection. This is called Total internal reflection. In the formation of a rainbow, Total Internal Reflection occurs at the rear of the raindrop - the water-to-air interface.

Based on the thermoelectric effect, the thermopile can be used as a heat sensor to measure thermal radiation. A thermopile is made of thermocouple junction pairs connected electrically in series. Thermocouples near the ground measures radiant energy.

Correct Option: D

Based on the thermoelectric effect, the thermopile can be used as a heat sensor to measure thermal radiation. A thermopile is made of thermocouple junction pairs connected electrically in series. Thermocouples near the ground measures radiant energy.

When a particle is moving in a uniform circular motion with constant speed and radius. the acceleration of the particle is given by v2/r. The particle will exhibit centripetal acceleration.

Correct Option: D

When a particle is moving in a uniform circular motion with constant speed and radius. the acceleration of the particle is given by v2/r. The particle will exhibit centripetal acceleration.

The blue colour of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the air. However, much of the shorter wavelength light is absorbed by the gas molecules. The absorbed blue light is then radiated in different directions. It gets scattered all around the sky.

Correct Option: A

The blue colour of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the air. However, much of the shorter wavelength light is absorbed by the gas molecules. The absorbed blue light is then radiated in different directions. It gets scattered all around the sky.