- 1(current)
Q. No.A transformer is used to light a \(100~\text{W}\) and \(110~\text{V}\) lamp from a \(220~\text{V}\) main. If the main current is \(0.5~\text{A},\) the efficiency of the transformer is approximately:
1. \(30\%\)
2. \(50\%\)
3. \(90\%\)
4. \(10\%\)
Subtopic: Â Transformer |
 74%
Level 2: 60%+
AIPMT - 2007
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The primary has \(100\) turns with \(100\) V RMS applied to it while the secondary has a total number of \(20\) turns, with the connection \(C\) made at the centre. The current \(i\) flowing towards \(C\) has the (RMS) value:
| 1. | \(2\) A | 2. | \(2\sqrt2\) A |
| 3. | \(\sqrt2\) A | 4. | zero |
Subtopic: Â Transformer |
 54%
Level 3: 35%-60%
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The primary coil of a transformer, when connected to a \(10~\text{V}\text-\)DC battery, draws a current of \(1~\text{mA}.\) The number of turns in the primary and secondary coils are \(50\) and \(100,\) respectively. The voltage across the secondary coil and the current drawn by the circuit in the secondary are respectively:
| 1. | \(20~\text{V}\) and \(2.0~\text{mA}\) |
| 2. | \(10~\text{V}\) and \(0.5~\text{mA}\) |
| 3. | zero and therefore no current |
| 4. | \(20~\text{V}\) and \(0.5~\text{mA}\) |
Subtopic: Â Transformer |
Level 3: 35%-60%
NEET - 2013
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A \(12~\text{V},60~\text{W}\) lamp is connected to the secondary of a step-down transformer, whose primary is connected to AC mains of \(220~\text{V}\). Assuming the transformer to be ideal, what is the current in the primary winding?
1. \(0.37~\text{A}\)
2. \(0.27~\text{A}\)
3. \(2.7~\text{A}\)
4. \(3.7~\text{A}\)
1. \(0.37~\text{A}\)
2. \(0.27~\text{A}\)
3. \(2.7~\text{A}\)
4. \(3.7~\text{A}\)
Subtopic: Â Transformer |
 74%
Level 2: 60%+
NEET - 2023
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- 1(current)
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