WAEC - Physics (2010 - No. 38)
A galvanometer of internal resistance 50\(\Omega\) and full scale deflection of 20 mA is converted into a voltmeter by connecting a resistor of resistance 1950\(\Omega\) in series to it. Calculate the maximum voltage that can be read by the voltmeter
20V
30V
38V
40V
解释
V = IR1 + IR2
= 0.02 x 50 + 0.02 x 1950 = 40V
= 0.02 x 50 + 0.02 x 1950 = 40V