Two heater wires, made of the same material and having the same length and the same radius, are first connected in series and then in parallel to a constant potential difference. If the rates of heat produced in the two cases are \(H_s\) and \(H_p\) respectively, then \(H_s / H_p\) will be

• A

  \(1 / 2\)
• B

  2
• Correct answer
  C

  \(1 / 4\)
• D

  4 .

Solution

When heater wires are connected in series, then equivalent resistance, $R_s=R_1+R_2=2 R \quad\left(\because R_1=R_2\right)$ Rate of heat produced, $H_s=\frac{V^2}{R_{\mathrm{s}}}$

Hence, the correct answer is option: 'C'.