JAMB - Physics (1982 - No. 25)
A high-resistance voltmeter reads 3.0V when connected across the terminals of a battery on open circuit and 2.6V when the battery supplies a current of 0.2A through a lamp. The resistance of lamp is
2.00\(\Omega\)
13.00\(\Omega\)
0.52\(\Omega\)
0.13\(\Omega\)
1.50\(\Omega\)
解释
IR = 2.6 and Ir = 0.4
0.2 x R = 2.6
R = 13.00\(\Omega\)
0.2 x R = 2.6
R = 13.00\(\Omega\)