Electricity

What does an electric circuit mean?

Define the unit of current.

Calculate the number of electrons constituting one coulomb of charge.

Name a device that helps to maintain a potential difference across a conductor.

What is meant by saying that the potential difference between two points is 1 V?

How much energy is given to each coulomb of charge passing through a 6 V battery?

On what factors does the resistance of a conductor depend?

Will current flow more easily through a thick wire or a thin wire of the same material, when connected to the same source? Why?

Let the resistance of an electrical component remains constant while the potential difference across the two ends of the component decreases to half of its former value. What change will occur in the current through it?

Why are coils of electric toasters and electric irons made of an alloy rather than a pure metal?

Draw a schematic diagram of a circuit consisting of a battery of three cells of 2 V each, a 5 Ω resistor, an 8 Ω resistor, and a 12 Ω resistor, and a plug key, all connected in series.

What determines the rate at which energy is delivered by a current?

An electric motor takes 5 A from a 220 V line. Determine the power of the motor and the energy consumed in 2 h.

A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R', then the ratio R/R' is –

Which of the following terms does not represent electrical power in a circuit?

An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be –

Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then parallel in a circuit across the same potential difference. The ratio of heat produced in series and parallel combinations would be –

How is a voltmeter connected in the circuit to measure the potential difference between two points?

A copper wire has diameter 0.5 mm and resistivity of $1.6 \times 10$⁻⁸ Ω m. What will be the length of this wire to make its resistance 10 Ω? How much does the resistance change if the diameter is doubled?

The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor are given below – I(amperes) 0.5 1.0 2.0 3.0 4.0 V(volts) 1.6 3.4 6.7 10.2 13.2 Plot a graph between V and I and calculate the resistance of that resistor.