- 1(current)
Q. No.A transformer has an efficiency of \(90\%\) working on \(200~\text V\) and \(3~\text{kW}\) power supply. If the current in the secondary coil is \(6~\text A,\) the voltage across the secondary coil and the current in the primary coil, respectively, are:
1. \(300~\text V,~15~\text A\)
2. \(450~\text V,~15~\text A\)
3. \(450~\text V,~13.5~\text A\)
4. \(600~\text V,~15~\text A\)
1. \(300~\text V,~15~\text A\)
2. \(450~\text V,~15~\text A\)
3. \(450~\text V,~13.5~\text A\)
4. \(600~\text V,~15~\text A\)
Subtopic: Â Transformer |
 77%
Level 2: 60%+
AIPMT - 2014
Hints
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
Hints
A \(220\) V input is supplied to a transformer. The output circuit draws a current of \(2.0\) A at \(440\) V. If the efficiency of the transformer is \(80\)%, the current drawn by the primary windings of the transformer is:
1. \(3.6\) A
2. \(2.8\) A
3. \(2.5\) A
4. \(5.0\) A
Subtopic: Â Transformer |
 78%
Level 2: 60%+
AIPMT - 2010
Hints
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
Hints
Links
The core of a transformer is laminated so that:
| 1. | energy losses due to eddy currents may be minimized |
| 2. | the weight of the transformer may be reduced |
| 3. | rusting of the core may be prevented |
| 4. | the ratio of voltage in primary and secondary may be increased |
Subtopic: Â Transformer |
 82%
Level 1: 80%+
AIPMT - 2006
Hints
Links
- 1(current)
Q. No.
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