Two sound waves X and Y have same amplitude and same wave pattern, but their frequencies are 60 Hz and 120 Hz respectively, then:

1. X will be shriller and Y will be grave
2. X will be grave and Y will be shriller
3. X will differ in quality than Y
4. X is louder than Y.

A nucleus of an atom consists of 146 neutrons and 95 protons. It decays after emitting an alpha particle. How many protons and neutrons are left in the nucleus after an alpha emission?

1. protons = 93, neutrons = 144
2. protons = 95, neutrons = 142
3. protons = 89, neutrons = 144
4. protons = 89, neutrons = 142

Assertion: Infrared radiations travel long distances through dense fog and mist.

Reason: Infrared radiations undergoes minimal scattering in earth's atmosphere

1. both assertion and reason are true.
2. both assertion and reason are false.
3. assertion is false but reason is true.
4. assertion is true reason is false.

Vibrations produced in a body under the influence of the periodic force is;

1. forced vibrations
2. resonant vibrations
3. damped vibrations
4. sympathetic vibrations