Question

A direct current of 2A and alternating current having a maximum value of 2A flow through two identical resistance. The ratio of heat produced in the two resistance will be:

• A. 1 : 1
• B. 1 : 2
• C. 2 : 1
• D. 4 : 1

Answer 1

The correct option is C 2 : 1

$\frac{Q_{DC}}{Q_{AC}}=\frac{i^{2}Rt}{i_{rms}^{2}Rt}=\frac{i^2}{{\left(\frac{i_0}{\sqrt{2}}\right)}^2}=2{\left[\frac{i}{i_0}\right]}^2$
$=2{\left[\frac{2}{2}\right]}^2=\frac{2}{1}$
$Q_{DC}:Q_{AC}=2:1$