A bat, flying at 7.00 m/s toward a wall, emits a chirp at 50.0 kHz. If the wall reflects this sound pulse, what is the frequency of the echo received by the bat? (vsound = 340 m/s)
a. 52.1 kHz
b. 51.1 kHz
c. 50.0 kHz
d. 49.0 kHz
e. 48.6 kHz
[Ques. 2] The function of the electric motor is which one of the following conversion processes?
a. mechanical energy to electrical
b. electrical energy to mechanical
c. low voltage to high or vice versa
d. alternating current to direct
[Ques. 3] While standing at a crosswalk, you hear a frequency of 600 Hz from an approaching police car. After the police car passes, its frequency is 400 Hz. What is the speed of the police car? (speed of sound = 340 m/s)
a. 34.0 m/s
b. 60.0 m/s
c. 66.3 m/s
d. 68.0 m/s
e. 199 m/s
[Ques. 4] The basic function of the electric generator is which of the following conversion processes?
a. mechanical energy to electrical
b. electrical energy to mechanical
c. low voltage to high or vice versa
d. alternating current to direct
[Ques. 5] A 550-Hz whistle is moved toward a listener at a speed of 25.0 m/s. At the same time, the listener moves at a speed of 35.0 m/s in a direction away from the whistle. What is the apparent frequency heard by the listener? (The speed of sound is 340 m/s.)
a. 510 Hz
b. 533 Hz
c. 655 Hz
d. 460 Hz
e. 594 Hz
[Ques. 6] The operation of an electric motor depends on which of the following effects?
a. the Doppler effect
b. the photoelectric effect
c. the force acting on a current-carrying wire in a magnetic field
d. current from the motion of a wire in a magnetic field
[Ques. 7] You stand by the railroad tracks as a train passes by. You hear a 1 020-Hz frequency when the train approaches, which changes to 760 Hz as it goes away. How fast is the train moving? The speed of sound in air is 340 m/s.
a. 30.2 m/s
b. 34.5 m/s
c. 40.1 m/s
d. 49.7 m/s
e. 45.6 m/s
[Ques. 8] A 0.200-m wire is moved parallel to a 0.500-T magnetic field at a speed of 1.50 m/s. What emf is induced across the ends of the wire?
a. 2.25 V
b. 1.00 V
c. 0.600 V
d. zero
[Ques. 9] An ambulance with its siren on is heading due east along a straight road at 60 mph. A car is also moving along the same road. In which case will the driver of the car perceive the frequency of the siren to be lowest?
a. The car is moving east at 65 mph and is behind the ambulance
b. The car is moving west at 65 mph and is behind the ambulance.
c. The car is moving east at 65 mph and is in front of the ambulance.
d. The car is moving west at 65 mph and is in front of the ambulance.
[Ques. 10] A large jetliner with a wingspan of 51.0 m flies horizontally and due north at a speed of 440 m/s in a region where the magnetic field of the earth is 48.4 T directed 30.0 below the horizontal. What is the magnitude of the induced emf between the ends of the wing?
a. 9.41E1 mV
b. 1.09E+0 mV
c. 5.43E1 mV
d. 3.26E+1 mV
e. 1.06E2 mV
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