The working of optical fibers is based on the _____ of electromagnetic waves.

1. 1. Polarization
   2. Reflection
   3. Refraction
   4. Total internal reflection

It takes much longer to cook things in the hills than in the than in the plains, because_____.

1. 1. Due to low atmospheric pressure in the hills the boiling point of water is raised and therefore, water takes longer to boil
   2. The humid atmosphere in the hills absorbs a lot of heat, leaving very little for the cooking
   3. Atmospheric pressure is high in the hills and water boils at a higher temperature
   4. Atmospheric pressure is lower and water boils at a lower temperature

What makes the air coming out of a punctured tyre cool?

1. 1. Isothermal expansion
   2. Flow at thigh speed
   3. Adiabatic expansion
   4. None of the above

The flow of heat from a hot to a cold body is an example of _____.

1. 1. Irreversible process
   2. Reversible process
   3. Adiabatic process
   4. Isothermal process

The weight of a given object is maximum _____.

1. 1. At the surface of the earth
   2. At the top of a mountain 5,000 ft high
   3. At the bottom of a 500 ft. deep mine
   4. At a distance of 100 km above the earth’s surface

The phenomenon of land and sea breeze is as a result of _____.

1. 1. Radiation
   2. Convection
   3. Conduction
   4. None of thses

When a beam of light is passed through a transparent medium, however, clear or homogeneous the medium may be, there is always a certain amount of light scattered sideways, out of the beam. This is known as _____.

1. 1. Raman effect
   2. Dispersion
   3. Rayleigh scattering
   4. None of the above

A polaroid is_____,

1. 1. A red light filter
   2. A devices used for analyzing polarized light
   3. A device used in polarimeter
   4. An adjustable shutter

Which of the following colour of light travel through, glass with minimum _____.

1. 1. Greed
   2. Red
   3. Yellow
   4. Violet

which of the following gives correct descending order of elasticity in the substances?

1. 1. Rubber, Silver, glass
   2. Steel, silver, rubber
   3. Silver, rubber, steel
   4. All have equal elasticity