Assertion: If temperature is increased, fundamental frequency of an open pipe will increase.

Reason: By increasing the temperature speed of sound wave will increase.

Assertion: In organ pipe experiment, loop size will decrease as the water column length is increased.

Reason: Frequency remains unchanged.

Assertion: In Doppler effect, if the source is moving, change in frequency is observed due to change in wavelength.

Reason: By the motion of source wavelength always decreases.

Assertion: Transverse mechanical wave does not travel in air.

Reason: Air has only bulk modulus of elasticity.

Assertion: A closed pipe and an open pipe cannot be in resonance with the same tuning fork, if the length of the closed pipe is integral multiple of the length of the open pipe.

Reason: An odd number is not divisible by an even number.

Assertion: No Doppler effect will be observed in sound when source and observer are moving with the same speed.

Reason: Doppler effect may be due to change in wavelength also.

Assertion: Ultrasonic is the acoustic analogue of ultraviolet radiation.

Reason: Ultraviolet rays do not produce visual sensations while ultrasonic waves are not heard by the human ear.

Assertion: Longitudinal waves are called pressure waves.

Reason: Propagation of longitudinal waves through a medium involves changes in pressure.

Assertion: If two people talk simultaneously and each creates a sound level of $60 \mathrm{dB}$ at a point $P$, then total sound level at the point $P$ is $120 \mathrm{dB}$.

Reason: Sound level is defined on a non-linear scale.