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प्रश्न
The current passing through an electric kettle has been doubled. The heat produced will become:
(a) half
(b) double
(c) four time
(d) one-fourth
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उत्तर
(c) four times
Heat produced is directly proportional to the square of the current.
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संबंधित प्रश्न
Name any two effects of electric current.
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(b) How much energy is transferred to the heater each second?
Name the material which is used for making the filaments of an electric bulb.
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What property of the filament wire accounts for this difference?
Three heaters each rated 250 W, 100 V are connected in parallel to a 100 V supply. Calculate:
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- the resistance of each heater and
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Solve the following example.
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Statement 2 : Heat in the resistor is created according to the rule of energy conservation.
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Rewrite the following statement by selecting the correct option:
1 A = ____________ mA.
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An electric iron consumes energy at the rate of 420 W when heating is at the maximum rate and 180 W when heating is at the minimum rate. The applied voltage is 220 V. What is the current in each case?
A fuse wire repeatedly gets burnt when used with a good heater. It is advised to use a fuse wire of:
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- How much power is dissipated in the circuit when all the three bulbs glow together?
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(c) Give a reason for your answer in (b).
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Name the effect of the current responsible for the glow of the bulb in an electrical circuit.
A trip switch is a ______ safety device.
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Find the odd one out.
Two students decided to investigate the effect of water and air on iron object under identical experimental conditions. They measured the mass of each object before placing it partially immersed in 10 ml of water. After a few days, the object were removed, dried and their masses were measured. The table shows their results.
| Student | Object | Mass of Object before Rusting in g |
Mass of the coated object in g |
| A | Nail | 3.0 | 3.15 |
| B | Thin plate | 6.0 | 6.33 |
What might be the reason for the varied observations of the two students?
