Page 419 - Basic Electrical Engineering

1. (b) 2. (d) 3. (c) 4. (a)

5. (a) 6. (c) 7. (c) 8. (c)

9. (a) 10. (a) 11. (b) 12. (b)

13. (b) 14. (a) 15. (a) 16. (b)

D. Multiple Choice Questions

(On single-phase ac circuits)

1. In an R–L series circuit, the power factor of the circuit is increased if

a. X , the inductive reactance is increased
L
b. X , the inductive reactance is decreased
L
c. R, resistance is decreased
d. the supply frequency is increased.

2. The power factor of an R–L circuit can be expressed as

a.

b.

c.

d. .

3. An R–L series circuit consists of R = 3 Ω and X = 4 Ω. The impedance of the circuit is
L

a. Z = 7 Ω
b. Z = 1 Ω
c. Z = 5 Ω