Kirchhoff's first law i.e. $\Sigma i=0$ at a junction is based on the law of conservation of :

(1) Charge

(2) Energy

(3) Momentum

(4) Angular momentum

The figure below shows currents in a part of electric circuit. The current i is

(1) 1.7 amp

(2) 3.7 amp

(3) 1.3 amp

(4) 1 amp

In the circuit shown, A and V are ideal ammeter and voltmeter respectively. Reading of the voltmeter will be

(1) 2 V

(2) 1 V

(3) 0.5 V

(4) Zero

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

The potential difference in open circuit for a cell is 2.2 volts. When a 4-ohm resistor is connected between its two electrodes the potential difference becomes 2 volts. The internal resistance of the cell will be :

(1) 1 ohm

(2) 0.2 ohm

(3) 2.5 ohm

(4) 0.4 ohm

A cell whose e.m.f. is 2 V and internal resistance is 0.1 Ω, is connected with a resistance of 3.9 Ω. The voltage across the cell terminal will be :

(1) 0.50 V

(2) 1.90 V

(3) 1.95 V

(4) 2.00 V

n identical cells each of e.m.f. E and internal resistance r are connected in series. An external resistance R is connected in series to this combination. The current through R is 

(1) $\frac{nE}{R+nr}$

(2) $\frac{nE}{nR+r}$

(3) $\frac{E}{R+nr}$

(4) $\frac{nE}{R+r}$

A cell of internal resistance r is connected to an external resistance R. The current will be maximum in R, if :

(1) R = r

(2) R < r

(3) R > r

(4) None of these

Two identical cells send the same current in 2 Ω resistance, whether connected in series or in parallel. The internal resistance of the cell should be 

(1) 1 Ω

(2) 2 Ω

(3) $\frac{1}{2}\Omega$

(4) 2.5 Ω

The internal resistances of the two cells shown are 0.1 Ω and 0.3 Ω. If R = 0.2 Ω, the potential difference across the cell :

(1) B will be zero

(2) A will be zero

(3) A and B will be 2V

(4) A will be > 2V and B will be < 2V