(a) live wire (b) neutral wire (c) earth wire (d) either earth or neutral wire Solution: The correct option is (a). A switch should be connected in the live wire.

(a) 15 A (b) 5 A (c) 10 A (d) Zero Solution: The correct option is (b). Rating of a fuse connected in lighting circuit is 5 A

Solution: Because the power circuit transports high-power and expensive gadgets, an earth wire is required in the power circuit. If there is an undesired power signal in the wire, it can destroy the...

Solution: In the following situations, an electrical device may cause an electric shock. (i) If the fuse is placed in the neutral wire and an excessive current flows in the circuit due to a...

(a) Name the three wires of the cable. (b) Between which of the two wires should the heating element of an electric geyser be connected? (c)To which wire should the metal case of the geyser be...

Solution: The colour coding of wires in a house wiring circuit aids in the proper wiring of switches, fuses, sockets, and other components.

Solution: (i) An earthing wire is a wire that is linked to the metallic body of an appliance and is green in colour. (ii) The wire that is attached to the appliance's switch is red in colour,...

Solution: The new international treaty states that (a) For live wire, use brown. (b) Neutral wire is light blue, and (c) Earth wire (green or yellow)

Solution: The paint creates an insulating layer on the appliance's metal body. As a result, the paint must be removed from the body portion where the earth connection will be formed.

(b) Name the part of the appliance which is earthed. Solution: (a) If the fuse is in the neutral wire, the fuse will burn due to the high current flow, but the appliance will remain at supply...

Solution: When a defective appliance's live wire comes into direct touch with its metallic cover for some reason. Then, the appliance gains the live wire's high potential. Because current passes...

Solution: In the house, near the kWh metre, local earthing is done. A hole roughly 2–3 metres deep is dug in the ground for this purpose. In the hole is put a copper rod covered by a hollow...

(a) Identify and write live (L), neutral (N) and earth (E) against the correct number. (b) To which part of the appliance is the terminal 1 connected? (c) To which wire joined to 2 or 3, is the fuse...

Solution: The letters E, N, and L stand for earth, neutral, and live wire, respectively.

Label the three pins. (a) Why is top pin thicker and longer than the other two? (b) Why are the pins split at the ends? Solution: The three pins in the plug are denoted as E, L and N. The earth pin...

Solution: All electrical appliances come with a wire with a plug on one end that is used to connect the device to the power supply. The top pin is for earthing, the left pin is for live, and the...

Solution: S1 and S2 are the two switches used. The switch S1 is installed at the bottom of the staircase, and the switch S2 is installed at the top. Figure 1 depicts the bulb in its off position...

Solution: In the event of an excessive current, connecting the switch to the neutral wire is harmful. Excessive current causes the fuse to blow, and the circuit's current to stop flowing. However,...

(b) Name the wire to which a switch is connected. Solution: (a) If water reaches the live wire, it forms a conducting layer between the hand and the live wire of the switch, allowing a current to...

(b) Why is the switch put in the live wire? (c) What precaution do you take while handling a switch? Solution: A switch is a device that controls the flow of current in a circuit by turning it on...

Solution: expression for the safe limit of current for the kettle is I = P/V Upon substituting values, we get I = 3000 / 250 = 12 A Yes, this kettle can be used in a circuit that contains a fuse of...

Solution: Expression for the safe limit of current that can flow through the electrical appliance is I = P / V Now, substituting the given values of P and v we get - => I = 5000 / 200 Therefore, I =...

Solution: When a fuse's current rating is 5 A, it signifies that if the circuit's current reaches 5 A, the fuse wire will melt.

Solution: (i) As the wire thickness increases, the current increases, allowing more electrons to travel through a larger area. As a result, 20 A wire will be thicker than 5 A wire. (ii) The length...

Solution: (i) The thickness of the fuse wire is proportional to the current rating of the fuse wire. The current rating will be higher if the fuse wire is thicker. (ii) The fuse wire's current...

Solution: If the fuse is placed in the neutral wire, and an excessive current flows in the circuit due to a malfunction in the appliance. The fuse will blow and the current will cease flowing in the...

Solution: The accompanying diagram depicts the most typical fuse setup. The fuse wire is strung between the two metallic terminals T1 and T2 in a porcelain holder. In this fuse setup (since...

Solution: Porcelain is an insulator of electricity. This is why the fuse wire in a porcelain holder is stretched between the two metallic terminals T1 and T2. This holder is designed to fit into a...

Solution: Porcelain is an insulator. Therefore, the fuse wire is fitted in a porcelain casing. The fuse is made out of a porcelain base with two metal contacts attached to it. These metal contacts...

(a) A fuse is a short piece of wire of high _________ and of material low _________. (b) A fuse wire is made of an alloy of ________ and ________. If the current in a circuit exceeds the current...

Solution: The fuse is a device that protects electric circuits from overloading and short circuit. It is based on the current's heating impact.

Solution: A safety device used to limit the current in an electric circuit is known as an electric fuse. The usage of a fuse protects the circuit as well as the appliances connected to it against...

(a) Charge (b) Current (c) Energy (d) Power Solution: The correct option is (c). Electrical meter in a house records the consumption of energy.

(a) Series (b) Parallel (c) Either in series or parallel (d) Both in series and parallel Solution: The correct option is (b). Electrical appliances in a house are connected in...

(a) Live wire (b) Neutral wire (c) Both the live and earth wires (d) Both earth and the neutral wire. Solution: The correct option is (a). Main fuse is connected in live...

(i) Explain the difference in the two sets, (ii) Which set of arrangement is preferred in the housing circuit and why? Solution: (i) In set A, all three bulbs are connected in series. The source...

(a) How is the bulb A connected with the mains? At what voltage does it glow? (b) How are the bulbs B and C connected with the mains? At what voltage does the bulb B glow? (c) How is...

Solution: In a building, all electrical equipment should be connected in parallel to the mains. Each electrical appliance has its own switch and fuse attached to the live wire. It ensures that...

Solution: The appliances here, are connected in a parallel arrangement to the mains.

Solution: The advantages of a ring system over a tree system are as follows: (i) Wiring in a ring system is less expensive than in a tree system. (ii) In a ring system, sockets and plugs of the same...

Solution: The main switch has an iron covering and is a twin pole switch. The main switch has the advantage of being able to break both the live and neutral wire connections at the same time. This...

Solution: Only the live wire before the main switch in the distribution board of a house circuit is connected in series with the main fuse.

Solution: The consumed electrical energy is measured by the electric meter in a home in kWh. 1 kWh = 3.6 × 106 J is the value of kWh in S.I. unit.

(a) kWh meter, (b) the main fuse, and (c) the main switch Solution: (a) The cable is connected to a kWh meter after the business fuse. Connections are made from this meter to a main switch and a...

Solution: A high-rated fuse is initially connected in the live wire at the pole or just before the meter before connecting the cable from the pole to the meter in a residence. The pole fuse is the...

(b) Which two wires mentioned in part (a) are at the same potential? (c) In which of the wire stated in part (a) the switch is connected? Solution: (a) The three connecting wires used in residential...

Solution: (a) To increase the voltage at the generating plant, a step-up transformer is put to use. (b) For its supply, a step-down transformer is employed to lower the voltage at the...

Solution: 220 V voltage and 50 Hz frequency.

Solution: At a power generating station, electric power is generated at 11 kV. From here, the alternating voltage is transmitted to the grid substation, where it is stepped up to 132 kV with the...

Solution: Power generated at generating stations is usually at 11 kV, which is a fairly high voltage. This energy will be transferred over long distances from the power plants. During the...

(b) What is the nature of the current transmitted from the power station? Solution: (a) Generation at voltages greater than 11 kV produces insulation problems. Whereas generation at voltages less...

Solution: At 11 kV and 50 Hz, the electric power is generated at the power generating station.