A current of 3 A is passed through a coil of resistance 75 Ω for 2 minutes. (a) How much heat energy is produced? (b) How much charge is passed through the resistance ?

(a) Given,

Current (I) = 3 A

Resistance (R) = 75 Ω

Time (t) = 2 min = 120 s

Heat produced = ?

Using

H = I²Rt

Substituting the values in the formula above, we get,

$H = 3^2 \times 75 \times 120 \\[0.5em] \Rightarrow H = 81000 \text{J}$

Hence, heat energy produced = 81000 J

(b) Charge passed through the resistance = ?

From relation,

Q = It

Substituting the values in the formula above we get,

$Q = 3 \times 120 \\[0.5em] \Rightarrow Q = 360 \text{ C}$

Hence, charge passed through the resistance = 360 C