Question

A new cell is marked 1.5 V. When connected to an external resistance, the voltmeter connected to its terminals reads 1.2 V. The drop in potential across the terminals of the cell is due to the:

Options

• internal resistance of cell

• external resistance

• both internal resistance of cell and external resistance

• none of these

Answer 1

Internal resistance of cell

Explanation:

When current flows, some potential is lost inside the cell because of its internal resistance. The terminal voltage is therefore lower than the cell’s e.m.f.