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

Answer

C

Explanation

Given that, first resistor, `R_(1) = 2 omega` and second resistor, `R_(2) = 4 omega` Voltage of cell, V = 6 V Time taken = t = 5 s Total resistance of the circuit = `R = R_(1) + R_(2) = 2 + 4 = 6 omega` Current, I = V`//`R = 6`//`6 = 1 A Heat dissipated by the 4 `omega` resistor in 5 s is given as, `H=I^(2)Rt`
` rarr H=1xx4xx5=20 j`