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Why does the cord of an electric heater not glow while the heating element does?
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Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.
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An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.
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An electric heater of resistance 8 Ω draws 15 A from the service mains 2 hours. Calculate the rate at which heat is developed in the heater.
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Why is the tungsten used almost exclusively for filament of electric lamps?
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Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal?
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How does the resistance of a wire vary with its area of cross-section?
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Write the molecular formula of first two members of homologous series having functional group -Cl.
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Write the molecular formula of first two members of homologous series having functional group −Br.
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Write the molecular formula of first two members of homologous series having functional group – OH
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The following vegetables are kept in a basket :
Potato, Tomato, Radish, Brinjal, Carrot, Bottle-gourd
Which two of these vegetables correctly represent the homologous structures?
(A) Carrot and Tomato
(B) Potato and Brinjal
(C) Radish and Carrot
(D) Radish and Bottle-gourd
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Write the molecular formula of the 2nd and 3rd member of the homologous series where the first member is ethyne.
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Write Joule's law of heating.
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An electric heater is connected to the 230 V mains supply. A current of 8 A flows through the heater.
(a) How much charge flows around the circuit each second?
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An electric heater is connected to the 230 V mains supply. A current of 8 A flows through the heater.
(b) How much energy is transferred to the heater each second?
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An electric room heater draws a current of 2.4 A from the 120 V supply line. What current will this room heater draw when connected to 240 V supply line?
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What is nichrome? State its one use.
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Give two reasons why nichrome alloy is used for making the heating elements of electrical appliances.
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Why are the coils of electric irons and electric toasters made of an alloy rather than a pure metal?
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How does the resistance of a wire vary with its:
diameter?
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