Rl Circuits(Electrical Engineering ) Questions and Answers
Question 1. A 1.2 kΩ resistor is in series with a 15 mH coil across a 10 kHz ac source. The magnitude of the total impedance is
152.6 Ω
1,526 Ω
1,200 Ω
942 Ω
Explanation:-
Answer: Option B. -> 1,526 Ω
Question 2. A 12 kΩ resistor is in series with a 90 mH coil across an 8 kHz ac source. Current flow in the circuit, expressed in polar form, is I = 0.3 ∠0° mA. The source voltage, expressed in polar form, is
3.84 ∠20.6° V
12.8 ∠20.6° V
0.3 ∠20.6° V
13.84 ∠69.4° V
Explanation:-
Answer: Option A. -> 3.84 ∠20.6° V
Question 3. When the frequency of the voltage applied to a series RL circuit is decreased, the impedance
Decreases
Increases
Does not change
Cannot be determined without values
Explanation:-
Answer: Option A. -> Decreases
Question 4. If a load is purely inductive and the reactive power is 12 VAR, the apparent power is
0 VA
12 VA
6 VA
24 VA
Explanation:-
Answer: Option B. -> 12 VA
Question 5. A 47 Ω resistor is in series with an inductive reactance of 120 Ω across an ac source. The impedance, expressed in polar form, is
47 ∠68.6° Ω
120 ∠68.6° Ω
129 ∠31.4° Ω
129 ∠68.6° Ω
Explanation:-
Answer: Option D. -> 129 ∠68.6° Ω
Question 6. If the frequency is halved and the resistance is doubled, the impedance of a series RL circuit
Doubles
Halves
Remains constant
Cannot be determined without values
Explanation:-
Answer: Option D. -> Cannot be determined without values
Question 7. When the frequency is decreased, the impedance of a parallel RL circuit
Increases
Decreases
Remains constant
Is not a factor
Explanation:-
Answer: Option B. -> Decreases
Question 8. When the frequency of the voltage applied to a series RL circuit is decreased, the impedance decreases
True
False
Explanation:-
Answer: Option A. -> True
Question 9. In an RL circuit, the impedance is determined by both the resistance and the inductive reactance combined.
True
False
Explanation:-
Answer: Option A. -> True
Question 10. A filter passes certain frequencies and rejects others.
