A milliammeter of range `10 mA` and resistance `9 Omega` is joined in a circuit as shown. The metre gives full-scale deflection for curretn `I` when `A` and `B` are used as its terminals, i.e., current enters at `A` and leaves at `B` (`C` is left isolated). The value if `I` is

Options

A. `100 mA`
B. `900 mA`
C. `1 A`
D. `1.1 A`

Answer

C

Explanation

(c ) Between `A` and `B`
`(9 + 0.9) xx 10 xx 10^(-3) = (I - 10 mA) xx 0.1`
`implies 990 mA = I - 10 mA implies I = 1000 mA = 1 A`