The diagram shows wiring in a meter room of a building. (a) What is the current rating of device X? (b) What is the difference between switch Z shown in the diagram and the switches used to operate different appliances at home? (c) What is the unit of the physical quantity displayed in Y?

(a) Which electrical component protects the electric circuit in case of excess current and which can also be used as a switch? (b) Name the wire to which this electrical component is connected in an electric circuit.

A fuse is rated 5 A. Can it be used with a geyser rated 1540 W, 220 V. Write Yes or No. Give supporting calculations to justify your answer.

Identify the option that displays the correct wiring with correct colour code: (a) (b) (c) (d)

An electric iron rated 1100 W, 220 V is operated for 5 hours. Calculate: (a) the minimum rating of the fuse required. (b) the energy consumed in kWh. (c) the cost of the energy consumed, if the rate is ₹10 per unit.

The reverse side of a three-pin plug with incorrect connection of wires is shown below. (a) Identify the fault in the above connection. (b) Mention a risk factor involved if the user operates the appliance without correcting it. (c) Will the appliance function in the present situation? (Yes or No)

The displacement–time graph of a sound wave produced by a vibrating wire is shown below. (a) How will you adjust the tension in the wire, to reduce the length of PR? (b) Which characteristic of sound is affected by the reduction in the length of PR?

A non-uniform kite is hanging freely from the branch of a tree as shown. Study the figure and answer the following: (a) Fill in the blank. ............... [P, Q, R or S] is the most probable position of its centre of gravity. (b) Support your answer to (a) with a reason.

A ray of light enters a rectangular glass slab submerged in water at an angle of incidence 55°. Does this ray undergo total internal reflection when it moves from water to glass? Justify your answer. (The critical angle for glass–water interface is 54°)

Calculate the amount of heat absorbed by 200 g of paraffin wax to melt completely at its melting point. [Specific latent heat of fusion of paraffin wax = 146 J g⁻¹]

(a) Which of the two, alternating current or direct current, produces a varying magnetic field when it flows through a conductor? (b) State the frequency of the alternating current supply in India.

A current flows through a metallic conductor for a long period of time. State the change you would expect in its: (a) Resistance (b) Resistivity