One or more options correct
Two cells of emf (internal resistance ) and (internal resistance ) are connected in parallel, positive terminal to positive terminal, and the combination is connected across an external resistor of . Which of the following statements is/are correct?
- A. The cell is being charged by the cell.
- B. The current through the resistor is .
- C. The equivalent emf of the parallel combination is .
- D. The potential difference across the resistor is .
Show answer and solution
Answer: A, B
Let be the common terminal voltage. Kirchhoff's current law at the positive node gives , i.e. , so . The current in the resistor is (B true) and the potential difference is , not (D false). The current in the cell is , while for the cell is negative: since the current enters its positive terminal, so it is being charged (A true). The equivalent emf of two parallel cells is , not (C false).
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