In the circuit given `E = 6.0 V, R_(1) - 100 ohms R_(2) =   R_(3) = 50 ohms R_(4) = 75 ohms`. The equivalent resistance of the circuit, in ohms, is

Options

A. `11.875`
B. `26.31`
C. `118.75`
D. none of these

Answer

c

Explanation

In given circuit three resistances `R_(2), R_(4)` and `R_(3)`are parallel.
Let initially resistance in the circuit is `ROmega` Thus, `V = I_(1) R = 5R`....(1)
When addition resistance of `2.0 Omega` is added in the circuit then
`V = 4(R + 2)`...(2)
As voltage across the resistance is same in both cases,
` :. 5R = 4R+ 8 impliesR=8Omega`
This resistance is in series with `R_(1)`
`:.R_( resultant) = R_(1) + R= 100+ 18.75 = 118.75 Omega`