Calculate the value of the resistance `R` in the circuit in the so that the current in the circuit is `0.2A`. What would be the potential difference between points `A and B` ?

Answer

` 5 Omega ,1 volt`

Explanation

Here resistor `5 Omega and 5 Omega` are is series .They together are in parallel to each of the resistors `30 Omega and 15 Omega`. Thus the effective resistance `(R_(eff))` between `A and B` is
`(1)/(R_(eff)) = (1)/(15) + (1)/(30) + (1)/((5 + 5)) = (18)/(90) = (1)/(5) or R_(eff) = 5 Omega`
The equivalent circuit is Effetive e.m.f. of the circuit `= 6 - 2 = 4V`

Current `I = (4)/(5+R+10) = 0.2 A`
or `4 = 3+ 0.2 or R = (4 - 3) 0.2 = 5 Omega`
Pot diff between `B and A = 5 xx 0.2 = 1.0 V`