In an electrical circuit, two resistors of `2 Omega and 4 Omega` respectively are connected in series to a `6 V` battery. The heat dissipated by the `4 Omega` resistor in `5 s` will be :

Options

A. 5 J
B. 10 J
C. 20 J
D. 30 J

Answer

C

Explanation

Given, resistors, `R_(1) = 2 Omega " and " R_(2) = 4 Omega`
Voltage, `V = 6 V_(1)` Time, t = 5s
Resistance, `R = 4 Omega`
Heat dissipated, H = ?
Resistor, `R_(s) = R_(1) + R_(2) = 2 + 4 = 6 Omega`
Current, `I = (V)/(R) = (6)/(6) = 1A`.
Heat dissipated `H = I^(2)Rt = 1 xx 4 xx 5 = 20 J`