Three cells each of emf, 1.0 V, and internal resistance, ...
Three cells each of emf, 1.0 V, and internal resistance, 2 Ω, are connected in parallel across a 3Ω resistor. Determine the current in the resistor.
0.90A
0.39A
0.30A
0.01A
Correct answer is C
Given Data: Emf = 1v, r = 2 ohms, R = 3 ohms, I = ?
3 resistance in parallel = 1r1 + 1r2 + 1r3
1rT= 12 + 12 + 12
1rT = 1+1+12
1rT = 32
cross multiply
rT = 23 or 0.67
E = I(R+r)
1 = I(3+0.67)
1 = I(3.67)
1 ÷ 3.67 = I
0.27 = I
: I ≈ 0.30A