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

Explanation

In the circuit shown here resistance of 5`Omega` joined between B and C, and resistance of 10`Omega` joined between C and D are in series and form a resistance of 15`Omega` . Now this resistance of 15`Omega` is in parallel arrangement with resistances of 10`Omega` and 30`Omega` between the points B and E. Hence equivalent resistance R. between B and E points is given by
`(1)/(R.) = 1/15 + 1/10 + 1/30 = 1/5 rArr R. = 5Omega`
So the equivalent circuit may be redrawn as in Fig. Applying Kirchhoff.s law to the circuit BEFAB, we have`
-0.2 xx 5 - 0.2 xx R-3-0.2 xx 15+8=0 `
` R = 5Omega`
and potential difference between B and E,
`V_B - V_E = 0.2 xx 5 = 1.0 V`