Physics Test 12...

For a certain orgain pipe, three successive resonance frequencies are observe at 425, 595 and 765 Hz. The speed of sound in air is 340ms^-1. The pipe is a

Identify the figure, which correctly represented the given wave function

The frequency of a note emitted by a source changes by 20% as it approaches stationary observer. As it recedes away from him the apparent frequency will be different from the actual frequency by (Velocity of sound in air is 340 m/s)

The linear density of a vibrating string is 10^-4 kg/m. A transerve wave is propagating on the string, which is described by the equation y=0.02sin(x 30t) where x and y are in meters and the time t is in seconds. The tension in the string is

A point source of sound produces a sound level of 30dB at a distance of 8m from it. At what distance from the source the sound level will be 36 dB

A string of length 0.4 m and mass 10^-2 kg is tightly clamped at its ends. The tension in the string is 1.6 N. Identical wave pulses are produced at one end at equal intervals of time Δt. The minimum value of ? t which allows constructive interference between successive pulses is

Assertion : To hear distinct beats, difference in frequencies of two sources should be less than 10

Reason : More the number of beats per sec more difficult to hear them

Assertion : The bells are made of metals and not of wood

Reason : Wood offers high damping to the sound waves

Assertion : For higher temperature, the peak emission wavelength of a black body shifts to lower wavelengths

Reason : Peak emission wavelength of a balck body is proportional to the fourth power of temperature

Assertion : A room can be cooled by opening the door of a refrigator in a closed room

Reason : Heat flows from lower temperature (refrigerator) to higher temperature (room)