In the circuit shown below, the cell has an e.m.f. of 10 V and internal resistance of 1 ohm. The other resistances are shown in the figure. The potential difference $V_A-V_B$ is :

(1) 6 V

(2) 4 V

(3) 2 V

(4) –2 V

In the circuit, the potential difference across PQ will be nearest to 

(1) 9.6 V

(2) 6.6 V

(3) 4.8 V

(4) 3.2 V

The e.m.f. of a cell is E volts and internal resistance is r ohm. The resistance in external circuit is also r ohm. The p.d. across the cell will be 

(1) E/2

(2) 2E

(3) 4E

(4) E/4

The terminal potential difference of a cell when short-circuited is (E = E.M.F. of the cell)

(1) E

(2) E/2

(3) Zero

(4) E/3