Question

Primary side of a transformer is connected to 230 V, 50 Hz supply. Turns ratio of primary to secondary winding is 10 : 1. Load resistance connected to secondary side is 46 \(\Omega \). The power consumed in it is :

• A. 12.5 W
• B. 10.0 W
• C. 11.5 W
• D. 12.0 W

Answer 1

The Correct Option is C

To find the power consumed by the load resistance connected to the secondary side of the transformer, we need to follow these steps:

1. Calculate the voltage across the secondary winding using the turns ratio. The turns ratio of the transformer is given as 10:1, meaning the primary winding has 10 times more turns than the secondary winding.
2. The voltage across the secondary (\( V_s \)) can be calculated using the formula for voltage transformation in transformers:

\( V_s = \frac{V_p}{\text{turns ratio}} \) 

1. where \( V_p = 230 \, \text{V} \) is the primary voltage.

\( V_s = \frac{230}{10} = 23 \, \text{V} \)

1. Using Ohm's Law, calculate the current flowing through the load resistance:

\( I_s = \frac{V_s}{R} \)

1. where \( R = 46 \, \Omega \).

\( I_s = \frac{23}{46} = 0.5 \, \text{A} \)

1. Calculate the power consumed by the load:

\( P = I_s^2 \times R \)

\( P = (0.5)^2 \times 46 = 0.25 \times 46 = 11.5 \, \text{W} \)

Therefore, the power consumed in the load resistance is 11.5 W.

The correct answer is 11.5 W.

Answer 2

Given:

\(\frac{V_1}{V_2} = \frac{N_1}{N_2} = 10 \implies V_2 = \frac{230}{10} = 23 \, \text{V}.\)

Power consumed:

\(P = \frac{V_2^2}{R} = \frac{23 \times 23}{46} = 11.5 \, \text{W}.\)

The Correct answer is: 11.5 W