Q164 / 170 · Manipal (MET) 2020 · Physics
On a heater coil it is written that, 250 V , 500 W . What is the resistance of this coil?
- A$62.5 \Omega$
- B$100 \Omega$
- C$200 \Omega$
- Correct answerD$125 \Omega$
Solution
Given $V=250 \mathrm{~V}$ and $P=500 \mathrm{~W}$
As we know that,
$P=\frac{V^2}{R}$
$\Rightarrow \quad R=V^2 / P=\frac{250 \times 250}{500}$
$=\frac{625}{5}=125 \Omega$
Hence, the correct answer is option: 'D'.