Question

A soldering iron draw an energy of 43200 J in 4min, when the current flowing through its element is 6 A, calculate the resistance of it's heating element​

Answer 1

Explanation:

Given,

Energy or heat produced , H = 43200J

Time period , t = 4min = 4 x 60 = 240 s

Current , I = 6A

Resistance, R = (?) ohm.

We know,

H = I^2RT

43200J = (6A)^2 x R x 240 s

43800 = 36 x R x 240

R = 43600/8640

R = 5 ohm

Therefore, Resistance is 5 ohm.