1 In the symbol for the electric cell, the longer line represents the ______ terminal and the thicker, shorter line represents the ______ terminal.
Answer: positive, negative
Explanation: The blank is filled with “positive” and “negative” as the passage explains that the longer line in the symbol of an electric cell represents the positive terminal, and the thicker, shorter line represents the negative terminal.
2 The wires used to connect the various components in a circuit are represented by ______.
Answer: lines
Explanation: The blank is filled with “lines” as the passage states that the wires used to connect the components in a circuit are represented by lines.
3 For some of the activities, we may need more than one ______.
Answer: cell
Explanation: The blank is filled with “cell” as the passage mentions that for some activities, multiple cells may be needed.
4 Many devices such as torches, transistors, toys, TV remote controls, use ______.
Answer: batteries
Explanation: The blank is filled with “batteries” as the passage mentions that many devices use batteries.
6 Sometimes the cells are placed side by side, and the terminals are connected by a thick wire or a ______ strip.
Answer: metal
Explanation: The blank is filled with “metal” as the passage describes that in some devices, when cells are placed side by side, the terminals are connected by a thick wire or a metal strip.
7 The ______ and ______ symbols are usually printed in the battery compartment to help in correctly placing the cells.
Answer: ‘+’ (plus), ‘-‘ (minus)
Explanation: The blanks are filled with “‘+'” (plus) and “‘-‘” (minus) as the passage states that these symbols are usually printed in the battery compartment to help in correctly placing the cells.
9 The bulb glows only when the switch is in the ‘______’ position and the electric circuit is ______.
Answer: ON, closed
Explanation: The blanks are filled with “ON” and “closed” as the passage mentions that the bulb glows only when the switch is in the ‘ON’ position and the electric circuit is closed.
10 If the filament of the bulb is broken, the bulb would not ______.
Answer: glow
Explanation: The blank is filled with “glow” as the passage states that if the filament of the bulb is broken, the bulb would not glow.
11 The heating effect of the electric current is observed when a thin wire called ________ gets hot.
Answer: filament
Explanation: The heating effect is observed when the filament of an electric bulb gets hot.
12 Wires made from special materials are used for making electric ________.
Answer: fuses
Explanation: Wires made from special materials are used for making electric fuses.
13 Electric fuses are inserted in electrical circuits to prevent damages caused by ________.
Answer: overheating
Explanation: Electric fuses protect against overheating and potential fires in electrical circuits.
14 The maximum limit on the current that can safely flow through a circuit is determined by the ________.
Answer: fuse
Explanation: A proper fuse in a circuit will blow off and break the circuit if the current exceeds the safe limit.
15 The filament of an electric bulb becomes so hot that it starts ________.
Answer: glowing
Explanation: The filament of an electric bulb gets heated to a high temperature and starts glowing.
16 Miniature circuit breakers (MCBs) automatically turn off the circuit when the current exceeds the ________.
Answer: safe limit
Explanation: MCBs turn off the circuit when the current exceeds the safe limit, acting as a safety measure.
17 Fluorescent tubes and CFLs are considered better electricity efficient lighting sources compared to ________ bulbs.
Answer: incandescent
Explanation: Fluorescent tubes and CFLs are better electricity efficient lighting sources compared to incandescent bulbs.
18 The ISI mark on electrical appliances indicates conformity to specified ________.
Answer: standards
Explanation: Using electrical appliances with the ISI mark, which assures conformity to specified standards.
19 When an electric current flows through a wire, the wire behaves like a __________.
Answer: Magnet
Explanation: When electric current passes through a wire, it behaves like a magnet.
20 An electromagnet can be made stronger by increasing the __________ of the wire.
Answer: Number of turns
Explanation: An electromagnet can be made very strong by increasing the number of turns of wire around the iron nail.
21 Electromagnets are used in cranes to lift heavy _________.
Answer: Loads
Explanation: Electromagnets can lift very heavy loads, and they are used in cranes for this purpose.
22 In an electric bell, the hammer strikes the _________ of the bell to produce sound.
Answer: Gong
Explanation: The hammer, attached to an iron strip, strikes the gong of the bell to produce a sound.
23 The coil in loses its magnetism when the electric current is _________ off.
Answer: Switched
Explanation: When the electric current is switched off, the coil generally loses its magnetism.
24 The circuit in an electric bell is repeatedly broken and completed by the movement of the _________.
Answer: Iron strip
Explanation: When the iron strip is pulled by the electromagnet, it breaks the circuit, and when it comes back in contact with the contact screw, it completes the circuit again.
25 Electromagnets are used to separate magnetic material from _________.
Answer: Junk
Explanation: lectromagnets are used to separate magnetic material from junk.
26 The needle of a compass is a tiny _________ that points in the north-south direction.
Answer: Magnet
Explanation: The needle of a compass is a tiny magnet.
27 Hans Christian Oersted was the first person to notice the deflection of a compass needle when an electric current flows through a _________ wire.
Answer: Nearby
Explanation:, Hans Christian Oersted noticed the deflection of a compass needle every time an electric current was passed through a nearby wire.
28 Electric fuses are made from wires that melt quickly and break when large electric _________ are passed through them.
Answer: Currents
Explanation: Electric fuses are made from wires that melt quickly and break when large electric currents are passed through them.