Practice Test: Question Set - 04
1. A 470 Ω resistor and a 0.2 μF capacitor are in parallel across a 2.5 kHz ac source. The admittance, Y, in rectangular form, is
- (A) 212 Ω
- (B) 2.12 mS
+ j3.14 mS
- (C) 3.14 mS
+ j2.12 mS
- (D) 318.3 Ω
2. For a certain load, the true power is 150 W and the reactive power is 125 VAR. The apparent power is
- (A) 19.52 W
- (B) 195.2 W
- (C) 275 W
- (D) 25 W
3. An imaginary number is one that exists only in the mind of the mathematician.
- (A) True
- (B) False
4. A positive angle of 30° is equivalent to a negative angle of
- (A) -30°
- (B) -330°
- (C) -60°
- (D) -180°
5. The power factor (PF) indicates how much of the apparent power is true power.
- (A) True
- (B) False
6. Apparent power is expressed in watts.
- (A) True
- (B) False
7. The complex number 40 ∠ 55° is equivalent to
- (A) 55 + j55
- (B) 40 + j40
- (C) 45.88
+ j65.52
- (D) 22.94
+ j32.76
8. The polar form of a complex number consists of a real part and a j part.
- (A) True
- (B) False
9. A filter passes all frequencies.
- (A) True
- (B) False
10. Total current in an RC circuit always leads the source voltage.
- (A) True
- (B) False
11. What is the value of the hypotenuse of a right triangle whose sides are 12 and 18?
- (A) 4.24
- (B) 3.46
- (C) 2.16
- (D) 21.63
12. In a lag network, the output voltage lags the input voltage in phase.
- (A) True
- (B) False
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