JAMB - Physics (1980 - No. 22)
A milliameter of resistance 5\(\Omega\) and full scale deflection of 50m A is to used to measure a potential difference of 50 V. The resistance of the multiplier should be
95\(\Omega\)
110\(\Omega\)
595\(\Omega\)
995\(\Omega\)
1005\(\Omega\)
Giải thích
V = IR
50 = 50 x 10\(^{-3}\) (5 + R)
R = 995\(\Omega\)
50 = 50 x 10\(^{-3}\) (5 + R)
R = 995\(\Omega\)