Find the shunt needed to extend the range of a 50Ω 1 mA

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Find the shunt needed to extend the range of a 50Ω 1 mA movement to (i) 2 mA, (ii) 10 mA:

1. 50,5·5Ω
2. 50,5Ω
3. 50,40Ω
4. 55,5·5Ω

Correct Option: A

The shunt resistance needed to extend the range of a 50Ω 1mA movement to
(i) 2mA
when I = 2mA
from the above figure it is clear that current in shunt resistance (R_sh) is 1mA.
So,

R_sh =	50 × 1mA	= 50Ω
	1mA

(ii) 10mA
In this case.

R_sh =	50 × 1mA
	9mA

or
R_sh = 5·5Ω (approximately)