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(d) Temperature remains constant.

Correct answer is (a) R/4

(b) decreases

Correct answer is (b) R₂ = 2R₁

Power = V x I 

Power (P) = Potential difference (V) x Current (I).

(c) Ohm meter

Flow of free electrons constitute the current.

A magnet formed temporarily due to the magnetic field of a current is called an electromagnet.

The phenomena of inducing an electric current in a coil by changing magnetic field around it is called electromagnetic induction.

1 ohm = \(\frac { 1 Volt }{ 1 ampere }\).

R= \(\frac { V }{ I }\) ,V = IR.

Electric motor, electric generator, loud speaker and measuring instruments.

(b) Potential difference

(d) More than 3 Ω

100 W shows the power of bulb, while 220 V shows the maximum potential difference required for proper functioning of bulb.

Parallel combination.

(a) Battery/cell

(d) All of the above

The purely resistive electric circuit is the one in which resistor is connected to battery such that the source energy gets dissipated entirely in the form of heat.

Correct answer is (b) 10 A

(d) Refrigerator

Transmission of current on long distant can result in lot of loss of electrical energy as the energy get transmitted into heat energy. Whereas in case of AC current the loss of electrical energy is less as the wire gets less heated.

When the fairy lights are connected in series the (total equivalent) resistance offered will be greater and the brightness of the bulbs will be affected. But in parallel connection all the bulbs will glow with same intensity and if any one bulb gets fused the other bulbs will continue to glow.

Heating effect of electric current has man room heaters, here the electric energy is deliberately made to get converted into heat energy.

(d) None of these

Magnitude of the induced current can be increased by 

1. increasing the number of coils of the wire. 

2. by increasing the power of magnet.

Resistance varies inversely as area of cross section.

(a) Voltage is dependent on I and R. Hence, in parallel circuit. 

(b) In parallel connection 

(c) In series connection

The magnitude of the magnetic field produced at the given point: 

1. Increases as the current through wire increases. 

2. Decreases as the distance from the wire increases.

(c) Values of current are different but value of potential difference is same

Work done by electric current in unit time is called electric power.

P = \(\frac { w }{ t }\)

Here, P is power, W is work done and t is time.

An electric potential (also called the electric field potential or the electrostatic potential) is the amount of electric potential energy that a unitary point electric charge would have if located at any point in space. Potential Difference: Difference in electric potential between two points in a circuit is called potential difference.

Correct answer is (b) 1: 3

We know that;

R = K x \(\frac { 1 }{ A }\)

If R₁ and R₂ are resistance of two wires and and A₂ are their areas of cross section then,

\(\frac { { R }_{ 1 } }{ { R }_{ 2 } }\) = \(\frac { l }{ { A }_{ 1 } }\) +\(\frac { l }{ { A }_{ 2 } }\)

\(\frac { { A }_{ 2 } }{ { A }_{ 1 } }\) = \(\frac { 11 }{ 2 }\)

Resistance is doubled because it is directly proportional to length.

(i) Copper is used as electrical transmission lines as it has lesser resistivity. 

(ii) Manganin is used for electrical heating device as it has the comparatively higher resistivity, less oxidation and variation with temperature.

Resistance \(R=\frac{pl}{A}=\frac{pl}{\pi r^2}\)

Resistivity ρ of manganin is much greater than that of copper, therefore to keep same resistance for same length of wire, the manganin wire must be thicker.

Correct answer is (d) 3.6 MJ

Correct answer is (b) 2 Ω

(a) Scalar quantity