Power Amplifiers » Exercise – 2
51. In class B power amplifiers, the output signal varies for ________ of the cycle.
(a) 360º
(b) 180º
(c) between 180º and 360º
(d) less than 180º
52. In ________ power amplifiers, the output signal varies for a full 360º of the cycle.
(a) class A
(b) class B or AB
(c) class C
(d) class D
53. Power amplifiers primarily provide sufficient power to an output load, typically from ________ to ________.
(a) a few kW, tens of kW
(b) 500 W, 1 kW
(c) 100 W, 500 W
(d) a few W, tens of W
54. Determine what maximum dissipation will be allowed for a 70-W silicon transistor (rated at 25ºC) if derating is required above 25ºC by a derating factor of 0.6 W/ºC at a case temperature of 100º.
(a) 25 W
(b) 30 W
(c) 35 W
(d) 40 W
55. Calculate the harmonic distortion component for an output signal having a fundamental amplitude of 3 V and a second harmonic amplitude of 0.25 V.
(a) 3.83%
(b) 38.3%
(c) 83.3%
(d) 8.33%
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