Four cells each of e.m.f 1.5V and internal resistance of 4Ω are connected in parallel. What is the effective e.m.f. and internal resistance of the combination?
Take Free Practice Test On 2026 JAMB UTME, Post UTME, WAEC SSCE, GCE, NECO SSCE
Correct Answer: Option D
Explanation:
Since all the cells are connected in parallel, the effective e.m.f. is just that of one single cell. Which means e.m.f. = 1.5V
However, the effective internal resistance adds as parallel arrangement given as
1/r = 1/r1 + 1/r2 + 1/r3 + 1/r4
= 1/4 + 1/4 + 1/4 + 1/4
= 1Ω
∴ r = 1Ω
Answer = 1.5V, 1Ω
Since all the cells are connected in parallel, the effective e.m.f. is just that of one single cell. Which means e.m.f. = 1.5V
However, the effective internal resistance adds as parallel arrangement given as
1/r = 1/r1 + 1/r2 + 1/r3 + 1/r4
= 1/4 + 1/4 + 1/4 + 1/4
= 1Ω
∴ r = 1Ω
Answer = 1.5V, 1Ω