A typical microwave oven operates at a frequency of 2.45 GHz. What is the wavelength associated with the electromagnetic waves in the oven?
1.8.20 m
2.12.2 cm
3.1.20 108 m
4.8.20 10-9 m
5.none of those answers
[Ques. 2] Which of the following statements are true regarding electromagnetic waves traveling through a vacuum? More than one statement may be correct.
1.All waves have the same wavelength.
2.All waves have the same frequency.
3.All waves travel at 3.00 108 m/s.
4.The electric and magnetic fields associated with the waves are perpendicular to each other and to the direction of wave propagation.
5.The speed of the waves depends on their frequency.
[Ques. 3] If the voltage across a circuit element has its maximum value when the current in the circuit is zero, which of the following statements must be true?
1.The circuit element is a resistor.
2.The circuit element is a capacitor.
3.The circuit element is an inductor.
4.The current and voltage are 90 out of phase.
5.The current and voltage are 180 out of phase.
[Ques. 4] A 6.00-V battery is connected across the primary coil of a transformer having 50 turns. If the secondary coil of the transformer has 100 turns, what voltage appears across the secondary?
1.24.0 V
2.12.0 V
3.6.00 V
4.3.00 V
5.none of those answers
[Ques. 5] A circuit containing an AC generator, a capacitor, an inductor, and a resistor has a high-Q resonance at 1 000 Hz. From greatest to least, rank the following contributions to the impedance of the circuit at that frequency and at lower and higher frequencies. Note any cases of equality in your ranking.
(a) XC at 500 Hz
(b) XC at 1 500 Hz
(c) XL at 500 Hz
(d) XL at 1 500 Hz
(e) R at 1 000 Hz
1.(c) > (d) > (a) > (e) > (b)
2.(a) > (d) > (b) > (c) > (e)
3.(b) > (c) > (a) > (d) > (e)
4.(d) > (a) > (e) > (c) > (b)
[Ques. 6] What is the phase angle in a series RLC circuit at resonance?
1.180
2.90
3.0
4.-90
5.None of these answers is necessarily correct.
[Ques. 7] Under what conditions is the impedance of a series RLC circuit equal to the resistance in the circuit?
1.The driving frequency is lower than the resonance frequency.
2.The driving frequency is equal to the resonance frequency.
3.The driving frequency is higher than the resonance frequency.
4.Always.
5.Never.
[Ques. 8] When a particular resistor is connected to a source of sinusoidally varying emf with constant amplitude and a frequency of 60.0 Hz, the rms current is 3.00 A. What is the rms current if the source frequency is doubled?
1.12.0 A
2.6.00 A
3.4.24 A
4.3.00 A
5.1.50 A
[Ques. 9] When a particular capacitor is connected to a source of sinusoidally varying emf with constant amplitude and a frequency of 60.0 Hz, the rms current is 3.00 A. What is the rms current if the source frequency is doubled?
1.12.0 A
2.6.00 A
3.4.24 A
4.3.00 A
5.1.50 A
[Ques. 10] When a particular inductor is connected to a source of sinusoidally varying emf with constant amplitude and a frequency of 60.0 Hz, the rms current is 3.00 A. What is the rms current if the source frequency is doubled?
1.12.0 A
2.6.00 A
3.4.24 A
4.3.00 A
5.1.50 A
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