For sound to travel through medium, it need not :

1. be rigid
2. be elastic
3. possess inertia
4. be frictionless

The speed of sound in air is not affected by change in :

1. temperature
2. moisture
3. pressure
4. density

The speed of sound in air at 0°C is nearly :

1. 1450 m s^-1
2. 450 m s^-1
3. 5100 m s^-1
4. 330 m s^-1

The speed of sound in a gas is related to temperature (in Kelvin) as :

1. directly proportional to temperature.
2. directly proportional to the square root of temperature.
3. inversely prtiportional to temperature.
4. inversely proportional to the square root of temperature.