Kirchhoff's Laws & Measuring Instruments
For the circuit shown, with R1 = 1.0 , R2 = 2.0 , E1 = 2 V and E2 = E3 = 4 V, the potential difference between the points 'a' and 'b' is approximately (in V):

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Answer: (a)
- Three branches lie between a and b: (, ), (, ), (, ), all with + towards a.
- Parallel-cell (Millman) formula:
- So the answer is (a) 3.3.