Question 2
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A single phase a.c. supply at 220 V, 50 Hz is applied to a series circuit consisting of 0.02H inductor and 15 Ω resistor. Calculate the:
(a) inductive reactance of the circuit;
(b)impedance of the circuit;
(c)current in the circuit;
(d)potential difference across the inductor;
(e)potential difference across the resistor.
OBSERVATION
The expected responses were:
For a single phase a.c. supplied series circuit
Voltage = 220 V,
Frequency = 50 Hz
Inductor = 0.02 H
Resistor = 15 Ω
(a) inductive reactance of the circuit;
XL = 2πfL
= 6.28 Ω
- Impedance of the circuit;
- current in the circuit;
- potential difference across the inductor;
- potential difference across the resistor.
VR = 
OR = 
= 203.0 V
This was well attempted by very many candidates. Only very few of those who attempted this question did not get either XL. Z, I, and/or pd across L and R correctly. Many did not put the unit of each answer.