A wire connected to a power supply of 230 V has power dissipation P₁. Suppose the wire is cut into two equal pieces and connected parallel to the same power supply. In this case power dissipation is P₂. The ratio \(\frac{P_2}{P_1}\) is ______.

In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be ______.

When 'n' resistors of equal resistance (R) are connected in series and in parallel respectively, then the ratio of their effective resistance is ______________

A potential difference is applied an the ends of a metallic wire. If the potential difference is doubled, the drift velocity ________________.

A bird sitting on an insulated wire carrying a current feels quite safe because ____________.

In an electric circuit fuse wire is connected in ________________.

Two identical resistors are connected in parallel then connected in series. The effective resistance are in the ratio ________________.

The drift velocity is equal to mobility when__________

Calculate the mobility of a free electron in an electric field of 10⁺²N/C.

A metal wire of current density is 3.2 x 10⁷ Am^-2 has 10²⁸ electron/m³. The average drift velocity is________

A potential of 1 kV is applied between the ends of conductor of length 20 cm. The drift velocity of electron in this field is 3.52 x 10⁶ m/s. The relaxation time for the free electrons is

The unit of conductivity is________

When three resistors are connected in parallel then the value of the effective resistance is________

Kirchhoff's I law is named as_____________

Kirchhoff's II law is named as_______

State microscopic form of Ohm’s law.

Define current density.

Define instantaneous current.

Distinguish between ohmic & non-ohmic device.

What is thermoelectric effect?

What is electric fuse?

How heating effect is used in electrical lamps? Name other lamps which use the heating effected.

What happens to the drift velocity of electron and to the resistance if length of conductor and to the resistance if length of conductor unchanged?

Nichrome and copper wire of same length and same radius are connected in series circuit I is passed through them. Which wire gets heated up more? Give reason.

Compute the current in the wire if a charge of 120 C is flowing through a copper wire in 1 minute.

If an electric field of magnitude 570 N C^–1, is applied in the copper wire, find the acceleration experienced by the electron.

A copper wire of cross-sectional area 0.5 mm² carries a current of 0.2 A. If the free electron density of copper is 8.4 x 10²⁸ m^-3 then compute the drift velocity of free electrons.

Two resistors when connected in series and parallel, their equivalent resistances are 15 Ω and \(\frac{56}{15}\)Ω respectively. Find the individual resistances.

Obtain the macroscopic form of Ohm’s law from its microscopic form and discuss its limitation.

Explain the equivalent resistance of a series and parallel resistor network.

Obtain the condition for bridge balance in Wheatstone’s bridge.

Derive an expression of drift velocity and write the relation between drift velocity and mobility.

(a) Distinguish between electric cells and batteries.
(b) Explain its function.

Find the expression for the equivalent emf & internal resistance of the series combination of cells.

Two electric bulbs marked 20 W – 220 V and 100 W – 220 V are connected in series to 440 V supply. Which bulb will get fused?

A battery has an emf of 12 V and connected to a resistor of 3 Ω. The current in the circuit is 3.93 A. Calculate
(a) terminal voltage and the internal resistance of the battery
(b) power delivered by the battery and power delivered to the resistor

Calculate the effect internal resistance in series and parallel.

A conductor of length I is connected to d.c. source of potential V. If the length of the conductor is doubled by treating it, keeping V constant, explain how do the following factors vary in the conductor
(i) Drift velocity.
(ii) Resistor
(iii) Resistivity.

Write mathematical relation between
(i) mobility & drift velocity of charge carriers in a conductor
(ii) mobility & relaxation time (or) mean free time.

A potential difference of 3 V is applied across a conductor through which the 5 A of current is flowing. Determine the resistance of the conductor.

A cell of emf E and internal resistance 'r' gives a current of 0.5 A with an external resistance of 12 \(\Omega \) and a current of 0.25 A with an external resistance of 25. Calculate
(i) internal resistance of the cell
(ii) emf of the cell.