The figure shows two point sources of light, A and B, that emit light waves in phase with each other. A is a distance of 3
from point P. B is distant 5
from P. (
is the wavelength.) The phase difference between the waves arriving at P from A and B is
a.
0 rad.
b.
rad.
c.
2
rad.
d.
3
rad.
e.
4
rad.
[Ques. 2] You are tuning a guitar by comparing the sound of the string with that of a standard tuning fork. You notice a beat frequency of 5 Hz when both sounds are present. You tighten the guitar string and the beat frequency rises steadily to 8 Hz. To tune the string exactly to the tuning fork, you should
1.continue to tighten the string.
2.loosen the string.
3.impossible to determine from the given information.
[Ques. 3] Balboa Park in San Diego has an outdoor organ. When the air temperature increases, the fundamental frequency of one of the organ pipes (the thermal expansion of the pipe is negligible)<--EndFragment--> runs
1.increases.
2.decreases.
3.stays the same.
4.is impossible to determine.
[Ques. 4] A pipe open at both ends resonates at a fundamental frequency fopen. When one end is covered and the pipe is again made to resonate, the fundamental frequency is fclosed. Which of the following expressions describes how these two resonant frequencies compare?
1. fclosed = fopen
2. fclosed = 3/2 fopen
3. fclosed = 2fopen
4. fclosed = 1/2 fopen
5.none of these
[Ques. 5] Which of the following frequencies are higher harmonics of a string with fundamental frequency of 150 Hz?
a)200 Hz
b)300 Hz
c)400 Hz
d)500 Hz
e)600 Hz
1.a
2.b and e
3.a, c, and e
4.d
[Ques. 6] As an airplane flying with constant velocity moves from a cold air mass into a warm air mass, the Mach number
1.increases.
2.decreases.
3.remains the same.
[Ques. 7] Suppose you're on a hot air balloon ride, carrying a buzzer that emits a sound of frequency f. If you accidentally drop the buzzer over the side while the balloon is rising at constant speed, what can you conclude about the sound you hear as the buzzer falls towards the ground?
1.The frequency and intensity increase.
2.The frequency decreases and the intensity increases.
3.The frequency decreases and the intensity decreases.
4.The frequency remains the same, but the intensity decreases.
[Ques. 8] Which of the following actions will increase the speed of sound in air?
1.decreasing the air temperature
2.increasing the frequency of the sound
3.increasing the air temperature
4.increasing the amplitude of the sound wave
5.reducing the pressure of the air
[Ques. 9] A pendulum clock depends on the period of a pendulum to keep correct time. Suppose a pendulum clock is keeping correct time and then Dennis the Menace slides the bob of the pendulum downward on the oscillating rod. The clock then runs
1.slow.
2.fast.
3.correctly.
[Ques. 10] A simple pendulum is suspended from the ceiling of a stationary elevator, and the period is measured. If the elevator accelerates upward, the period
1.increases.
2.decreases.
3.remains the same.
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