In the given circuit current flowing through the resistance `20Omega` is `0.3A,` while the ammeter reads 0.8 A. What is the value of `R_1`

Options

A. `30 ohm`
B. `40 ohm`
C. `50 ohm`
D. `60 ohm`

Answer

D

Explanation

(d) `V = 20 xx 0.3 = 6 V`
`I_(2) = (6)/(15) = 0.4 A`
`I = I_(1) + 0.3 +l_(2)`
`implies 0.8 = I_(1) + 0.3 + 0.4`
`implies I_(1) = 0.1 A, R_(1) = (V)/(1) = (6)/(0.1) = 60 Omega`