Electric Curren...

A brass disc and a carbon disc of same radius are assembled alternatively to make a cylindrical conductor. The resistance of the cylinder is independent of the temperature. The ratio of thickness of the brass disc to that of the carbon disc is ______. α is temperature coefficient of resistance & Neglect linear expansion

Out of the following which is not a poor conductor ?

 Under what condition current passing through the resistance R can be increased by short circuiting the battery of emf E₂. The internal resistances of the two batteries are r₁ and r₂ respectively.

 ABCD is a square where each side is a uniform wire of resistance 1Ω. A point E lies on CD such that if a uniform wire of resistance 1W is connected across AE and constant potential difference is applied across A and C then B and E are equipotential.

Two current elements P and Q have current voltage characteristics as shown below :

Which of the graphs given below represents current voltage characteristics when P and Q are in series.

Power of battery in resistor appears as

A simple circuit contains an ideal battery and a resistance R. If a second resistor is placed in parallel with the first.

 Consider the circuit shown in the figure

A copper wire of radius 0.1 mm and resistance 1 kW is connected across a power supply of 20 V. How many electrons are transferred per second between the supply and the wire at one end ?

A car has a fresh storage battery of emf 12 V and internal resistance 5.0 × 10^-2W. If the starter draws a current of 90 A, what is the terminal voltage of the battery when the starter is on ?