11. A resistance of 7 ohms is connected in series with an inductance of 31.8mH. The circuit is connected to a 100V 50Hz sinusoidal supply. Calculate the voltage across the resistor.
A. 31.8V
B. 57.4V
C. 67.3V
D. 78.2V
12. A resistance of 7 ohms is connected in series with an inductance of 31.8mH. The circuit is connected to a 100V 50Hz sinusoidal supply. Calculate the voltage across the inductor.
A. 52V
B. 82V
C. 65V
D. 76V
13. A resistance of 7 ohms is connected in series with an inductance of 31.8mH. The circuit is connected to an x V 50Hz sinusoidal supply. The current in the circuit is 8.2A. Calculate the value of x.
A. 10V
B. 50V
C. 100V
D. 120V
14. Which, among the following, is the correct expression for φ.
A. φ = tan-1 (XL/R)
B. φ = tan-1 (R/XL)
C. φ = tan-1 (XL × R)
D. φ = cos-1 (XL/R)
15. For an RL circuit, the phase angle is always ________
A. Positive
B. Negative
C. 0
D. 90
16. What is φ in terms of voltage?
A. φ = cos-1V/VR
B. φ = cos-1V × VR
C. φ = cos-1VR/V
D. φ = tan-1V/VR
17. What is sinϕ from the impedance triangle?
A. XL/R
B. XL/Z
C. R/Z
D. Z/R
18. What is the resonance frequency of ac circuit?
A. 1/√LC
B. √(L/C.
C. √LC
D. LC
19. What is impedance at resonance?
A. maximum
B. minimum
C. zero
D. cannot be determined
20. What is the value of impedance at resonance?
A. XL
B. XC
C. R
D. 0