A lamp is first connected across one cell, and then across two cells. In each arrangement, the potential difference (p.d.) across the lamp and the current through it are measured. How does the lamp’s resistance change when the number of cells is increased from one to two?
- AIt decreases by $0.015\,\Omega$.
- BIt increases by $1.5\,\Omega$.
- CIt increases by $2.3\,\Omega$.
- DIt increases by $17\,\Omega$.