Current Electricity

A circuit consists of three batteries of emf E₁ = 1 V, E₂ = 2 V and E₃ = 3 V and internal resistances 1 Ω, 2Ω and 1 Ω respectively which are connected in parallel as shown in the figure. The potential difference between points P and Q is

• 1.0 V

• 2.0 V

• 2.2 V

• 3.0 V

The current I is in the circuit shown is

• 1.33 A

• Zero

• 2.00 A

• 1.00 A

A metal wire of circular cross-section has a resistance R₁. The wire is now stretched without breaking, so that its length is doubled and the density is assumed to remain the same. If the resistance of the wire now becomes R₂ then R₂ : R₁ is

• 1 : 1

• 1 : 2

• 4 : 1

• 1 : 4

Assume that each diode as shown in the figure has a forward bias resistance of 50 Ω and an infinite reverse bias resistance. The current through the resistance 150 Ω is

• 0.66 A

• 0.05 A

• Zero

• 0.04 A

Two cells A and B of emf 2V and 1.5 V respectively, are connected as shown in figure through an external resistance 10 Ω. The internal resistance of each cell is 5 Ω. The potential difference E_A and E_B across the terminals of the cells A and B respectively are

• E_A = 2.0 V, E_B = 1.5 V

• E_A = 2.125 V, E_B  = 1.375 V

• E_A = 1.875 V, E_B = 1.625 V

• E_A = 1.875 V, E_B = 1.375 V