Question 357: Current Electricity

Question

For the circuit shown, with R
1
= 1.0W, R
2
= 2.0 W,
E
1
= 2 V and E
2
= E
3
= 4 V, the potential
difference between the points 'a' and 'b' is
approximately  (in V):

Accepted Answer

Given circuit is
Above circuit can be viewed as
This is a parallel combination of three cells or in other words, a parallel grouping of three cells with internal resistances.
So, $${V_{ab}} = {E_{eq}} = {{{I_{eq}}} \over {{r_{eq}}}} = {{{{{E_1}} \over {{r_1}}} + {{{E_2}} \over {{r_2}}} + {{{E_3}} \over {{r_3}}}} \over {{1 \over {{r_1}}} + {1 \over {{r_2}}} + {1 \over {{r_3}}}}}$$
$$ = {{{2 \over 2} + {4 \over 2} + {4 \over 2}} \over {{1 \over 2} + {1 \over 2} + {1 \over 2}}} = {{10} \over 3}V \approx 3.3\,V$$

Answer

3.3

Answer

2.7

Answer

2.3

Answer

3.7

Current Electricity

For the circuit shown, with R 1 = 1.0W, R 2 = 2.0 W, E 1 = 2 V and E 2 = E 3 = 4 V, the potential difference between the points 'a' and 'b' is approximately (in V):

Choose the correct answer: