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Name three main characteristics of an heating element.
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Mention three uses of the carbon arc.
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Name two common material used for heating elements.
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In an electric radiator or room heater, state with reason, why the porcelain tube wound with a nichrome wire is placed between the pole and principal focus of the parabolic concave reflector.
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Why is heating element wound on a long porcelain rod in a room heater.
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Why is a concave reflector placed behind the heating element in a room heater.
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State the position of heating element with respect to principal focus of concave reflector and give reason for choosing this position.
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Household wiring for lamp connections can either be done in parallel or in series.Which one would you prefer? Give a reason for your answer.
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Why is the heating element of an electric oven wound on a helix? State the reason.
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The electric bulbs used these days have a coil-coiled filament. State its reason.
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What changes in energy occur in an electric bulb?
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What changes in energy occur in an electric heater?
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An electric filament lamp is connected to a supply of voltage higher than the recommended value. Give reasons, why compared with a normal performance, the lamp emits a brighter light and its life is shortened.
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‘The current rating of a fuse is 5A’. Comment on this statement.
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Two lamps are rated 220V, 50W and the other rated 220V, 100W are connected in series with the mains of 220 V. Explain, why the 50W lamp glows more?
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Why does not the heating coil produce any visible light? in an electric stove.
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Of the three connecting wires in a household circuit: Which two of the three wires are at the same potential? In which of the three wires should the switch be connected?
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State two advantages of filling an inert gas in an evacuated electric filament lamp.
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A device is used to transform 12 V a.c. to 200 V a.c. What is the name of this device? Name the principle on which it works.
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Which material is the calorimeter commonly made of? Give one reason for using this material.
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