Question

A galvanometer with coil resistance 12.0ohms show full scale deflection for a current of 2.5mA.How would you convert it into a voltmeter of range 0 to 10.0v
a) 3988 ohms in series
b) 0.4 ohms in parallel
c) 2000 ohms in parallel
d) 1.62 ohms in series

Answer 1

Answer on Question #50959-Physics-Electromagnetism

A galvanometer with coil resistance $G = 12.0$ ohms show full scale deflection for a current of $I_g = 2.5$ mA. How would you convert it into a voltmeter of range 0 to 10.0 V?

a) 3988 ohms in series

b) 0.4 ohms in parallel

c) 2000 ohms in parallel

d) 1.62 ohms in series

Solution

$$V = 10.0\,V, R = ?$$ $$R = \frac{V}{I_g} - G = \frac{10.0}{2.5 \cdot 10^{-3}} - 12.0 = 3998\, \text{ohms}.$$

Answer: a) 3988 ohms in series.

http://www.AssignmentExpert.com/