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Identify the figure and give its use.

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Heat energy is being produced in a resistance in a circuit at the rate of 100 W. The current of 3 A is flowing in the circuit. What must be the value of the resistance?
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Solve the following example.
Two tungsten bulbs of wattage 100 W and 60 W power work on 220 V potential difference. If they are connected in parallel, how much current will flow in the main conductor?
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An electric iron of 1100 W is operated for 2 hrs daily. What will be the electrical consumption expenses for that in the month of April? (The electric company charges Rs 5 per unit of energy).
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Solve the following example.
Three lenses having power 2, 2.5 and 1.7 D are kept touching in a row. What is the total power of the lens combination?
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Explain the term of Metallurgy .
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Statement 1 : Electric current ( flow of electrons ) creates heat in the resistor.
Statement 2 : Heat in the resistor is created according to the rule of energy conservation.
Explain Statement 1 with the help of Statement 2.
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Statement 1 : Electric current ( flow of electrons ) creates heat in the resistor.
Statement 2 : Heat in the resistor is created according to the rule of energy conservation.
Explain Statement 1 with the help of Statement 2.
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Complete the following flow chart and answer the questions below:

i) In which method pine oil is used?
ii) Explain what method of concentration in brief.
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i) Observe the following reaction and answer the following questions.
`CuSO_4 (aq) + Fe (s) → FeSO_4(aq) + Cu (s)`
a) Identify and write the type of chemical reaction.
b) Write the definition of above reaction.
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Why does tungsten metal used to make solenoid type coil in an electric bulb?
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Observe the figure and answer the following questions.
a) Identify the machine shown in figure.
b) Write a use of this machine.
c) How transformation of energy takes place in this machine.

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When heat energy is absorbed by object ΔT represents the raise in temperature. What would be ΔT represent if the object loses heat energy?
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Give scientific reason :
In the electric equipment producing heat e.g. iron, electric heater, boiler, toaster, etc., an alloy such as Nichrome is used, not pure metals.
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Write names of first four homologous series of alcohols.

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Answer the following question:
Grills of doors and windows are always painted before they are used? Give reason.
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Answer the following:
What is corrosion? Do gold ornaments corrode? Justify.
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Name any six domestic appliances based on the heating effect of electric current.
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Explain the construction and working of an electric generator (AC) with the help of a neat diagram.
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Rewrite the following statement by selecting the correct option:
1 A = ____________ mA.
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