Current Electri...

Two cells of equal e.m.f. and of internal resistances r₁ and r₂(r₁> r₂)are connected in series. On connecting this combination to an external resistance R, it is observed that the potential difference across the first cell becomes zero. The value of R will be

When connected across the terminals of a cell, a voltmeter measures 5 V and a connected ammeter measures 10 A of current. A resistance of 2 ohm is connected across the terminals of the cell. The current flowing through this resistance will be

In the circuit shown below E₁ = 4.0 V, R₁ = 2 Ω, E₂ = 6.0 V, R₂ = 4 Ω and R₃ = 2 Ω. The current I₁ is

An ionization chamber with parallel conducting plates as anode and cathode has 5 × 10⁷ electrons and the same number of singly-charged positive ions per cm³.
The electrons are moving at 0.4 m/s. The current density from anode to cathode is 4 μA/m². The velocity of positive ions moving towards cathode is

What is the equivalent resistance between the points A and B of the network?

In the circuit element given here, if the potential at point B, V_B = 0, then the potentials of A and D are givenas

The equivalent resistance between the points P and Q in the network given here is equal to (given r = 3/2 Ω)

The resistance of a wire of iron is 10 ohm and temp. Coefficient of resistance is 5 × 10^–3/° C. At 20°C itcarries 30 milliampere of current. Keeping constant potential difference between its ends, the temperature of the wire is raised to 120°C . The current in milliampere that flows in the wire is

In the circuit shown here, the readings of the ammeterand voltmeter are

Length of a hollow tube is 5m, its outer diameter is 10 cm and thickness of its wall is 5 mm. If resistivity of the material of the tube is 1.7 × 10^–8Ω× m thenresistance of tube will be