Question

A uniform wire is cut in to 3 parts with their lengths in the ratio 2:3:6 the ends of each three parts connected along a ideal battery of 10v if a current of 5 ampere drawn from battery find the initial resistance

Answer 1

Thus the initial resistance is 2 Ω

Explanation:

We know that

I = V / R

5 = 10 V / R

R = 10 / 5 = 2 Ω

Or

Now

(1) 2 / 11 x 2 = 4 / 11 Ω

(2) 3 / 11 x 2 = 6 /11 Ω

(3) 6 / 11 x 2 = 12 / 11 Ω

R = 1 / R1 + 1 / R2 + 1/R3

R = 4 + 6 + 12 / 11 = 22 / 11 = 2 Ω

Thus the initial resistance is 2 Ω