Practice Test: Question Set - 01
1. When the frequency of the source voltage decreases, the impedance of a parallel RC circuit
- (A) Increases
- (B) Decreases
- (C) Does
not change
- (D) Decreases
to zero
2. An ac circuit consists of a resistor and a capacitor. To increase the phase angle above 45°, the following condition must exist:
- (A) R = XC
- (B) R > XC
- (C) R < XC
- (D) R =
5XC
3. In a series RC circuit, when the frequency and the resistance are halved, the impedance
- (A) Doubles
- (B) Is
halved
- (C) Is
reduced to one-fourth
- (D) Cannot
be determined without values
4. The impedance of a series RC circuit varies directly with frequency.
- (A) True
- (B) False
5. A 120 Ω resistor is in parallel with a capacitor with a capacitive reactance of 40 Ω. Both components are across a 12 V ac source. What is the magnitude of the total impedance?
- (A) 37.9 Ω
- (B) 3.7 Ω
- (C) 14,400 Ω
- (D) 4,800 Ω
6. A capacitor with 150 Ω of capacitive reactance is across an ac source. The impedance, expressed in polar form, is
- (A) Z =
150
- (B) Z =
150 ∠90°Ω
- (C) Z =
150 ∠-90°Ω
- (D) Z =
150 ∠180°Ω
7. When the frequency of the voltage applied to a series RC circuit is increased, the phase angle
- (A) Increases
- (B) Decreases
- (C) Remains
the same
- (D) Becomes
erratic
8. The complex number 6 + j6 is equivalent to
- (A) 6 ∠45°
- (B) 36 ∠45°
- (C) 8.48 ∠45°
- (D) 8.48 ∠90°
9. Complex numbers can be added and subtracted but not multiplied or divided.
- (A) True
- (B) False
10. In the complex plane, the number 14 - j5 is located in the Fourth quadrant
- (A) True
- (B) False
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