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GURUKUL CENTRAL ACADEMY, CH.- 13. ELECTRICITY AND, CIRCUIT, , WORKSHEET-1, Refer text book, WORKSHEET-2, Refer text book, WORKSHEET-3, Refer text book, , TEXTBOOK EXERCISES, Page 150 Try These, 1. electric, 2. radio 3. solar, , 4. tungsten 5. Good
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GURUKUL CENTRAL ACADEMY, EXERCISES, A. 1. c., , 2. d., , B. 1. cell, 4. Conductors, C., , 3. b. 4. c. 5. b., 2. switch, 5. fuse, , 6. a., , 7. c, , 8. d. 9. a., , 3. tungsten, 6. positive, negative, , 1. – c., 2. – e., 3. – a., 4. – b., 5. – d., , D., , 1. Argon, 2. Positive terminal, Negative terminal, 3. Filament, 4. Insulator, 5.Fuse, , E., , 1. Dry cell is a primary cell which produces electricity from the, chemical stored inside it., 2., , Electric current is flow of electricity through an electric circuit., , 3., , Electric circuit is a path around which an electric current flows., , 4., , The electric circuit in which contact among any of the, components of the circuit is broken is called an open circuit., The electric circuit in which the current flows from one terminal, of the cell to another terminal is known as a closed circuit.
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GURUKUL CENTRAL ACADEMY, , F., , 5., , Electric switch is important to turn an electric appliance, ‘on’ and ‘off’., , 6., , Because rubber is a bad conductor of electricity., , 7., , It is because path of the current is broken and the circuit becomes, open., , 8., , So that naked wires may not give an electric shock to the user., , 1., , 2., , A simple dry cell consists of a container made up of zinc can., Inside the container is a carbon rod surrounded by a mixture of, powdered carbon and manganese dioxide. A paste of ammonium, chloride surrounds this mixture from outside. The cell is sealed, from the top, to prevent the ammonium chloride paste from drying, up. In this cell the carbon rod acts as the positive terminal (anode), and the zinc casing which reacts with ammonium chloride paste, (electrolyte), acts as the negative terminal (cathode). Due to the, chemical reaction that takes place inside the cell, electricity is, generated that flows from the positive to negative terminal., Refer diagram 13.4 from page 146.
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GURUKUL CENTRAL ACADEMY, , 3., , An electric bulb has a thin wire called filament, which is made up, of tungsten. The filament is enclosed in a glass case which is filled, with an inert (that does not react with any element) gas such as, argon, or neon. The filament is connected to two thick wires inside, the bulb. One of those wires is connected to the metal case of the, bulb. The other, is connected to the metal tip at the bottom. The metal case and the, metal tip are the two terminals of the bulb. On passing current, through the terminals, the electric bulb produces light., , 4., , Conductors: 1. The materials that allow electricity to pass through, them are called conductors. 2. For example iron, copper and, graphite., Insulators: 1. The materials that do not allow electricity to pass, through them are called insulators. 2. For example plastic, glass and, rubber., , 5., , • Do not touch bare part of an electrical wire., • Make sure you wear rubber slippers while handling or, turning on and off electrical gadgets., • Keep your hands dry while handling electrical equipment because, moisture increases conductivity and you may get shock., • Do not use electrical socket at your home for, conducting any experiments.
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GURUKUL CENTRAL ACADEMY, , 6., , The torch consists of a simple circuit which operates with the help, of batteries and a switch. In a torch, there is a metal spring at the, base which is connected to slide switch. Another metal strip is, connected to a bulb as shown in given figure. The base of the torch, bulb is in contact with the cells which complete the circuit by, coming in contact with the metal spring. The reflector helps in, throwing a parallel beam of light, which spreads throughout the, area. When the switch is in ‘On’ position, the circuit is closed and, the bulb glows., Refer diagram 13.21 from page 151.
