A $12\,\text{V}$, $36\,\text{W}$ lamp glows at its normal brightness when it is attached to a mains transformer. Take the transformer to be $100\%$ efficient. Which row gives the number of turns in the secondary coil and the current in the mains wires?
- Anumber of turns in secondary coil $=60$, current in the mains wire $=0.15\,\text{A}$
- Bnumber of turns in secondary coil $=60$, current in the mains wire $=3.0\,\text{A}$
- Cnumber of turns in secondary coil $=180$, current in the mains wire $=0.15\,\text{A}$
- Dnumber of turns in secondary coil $=180$, current in the mains wire $=3.0\,\text{A}$