KCET 2025 Physics Paper

To find the equivalent electromotive force (emf) of the two cells connected in parallel, we use the formula for the equivalent emf, E‌eq ‌, which is given by:
Eeq=‌

‌ E1 r1 + E2 r2

1 r1 +‌ 1 r2

=‌

E1r2+E2r1

r1+r2

This result represents the combined effect of the two cells' emfs and their internal resistances. The equivalent emf E‌eq ‌ will lie between E1 and E2. Given that E2>E1 and r2>r1, the equivalent emf E‌eq ‌ will be closer to E2 rather than E1 because the cell with the larger emf and larger internal resistance will have a more significant influence on the total emf value. Therefore, it can be concluded that E1<E‌eq ‌<E2, and E‌eq ‌ is nearer to E2.