A galvanometer having a coil of resistance 30Ω need 20 mA of current for full-scale deflection. If a maximum current of 3 A is to be measured using this galvanometer, the resistance of the shunt to be

Question

A galvanometer having a coil of resistance $30Ω$ need 20 mA of current for full-scale deflection. If a maximum current of 3 A is to be measured using this galvanometer, the resistance of the shunt to be added to the galvanometer should be $\frac{30}{X} Ω$ , where $X$ is Options

Options:

Answer:

B

Solution:

$(I - I_{g}) R = I_{g} G (3 - 0.02) \times R = 0.02 \times G \Rightarrow R = \frac{30}{149} \Rightarrow 149 = Required X$

TestHub · Accepted Answer

​ ( I − I g ​ ) R = I g ​ G ( 3 − 0.02 ) × R = 0.02 × G ⇒ R = 149 30 ​ ⇒ 149 = Required X ​

Physics - Current Electricity Question with Solution | TestHub

Options:

Doubts & Discussion