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प्रश्न
Find the odd one out and give its explanation.
विकल्प
Tungsten
Nichrome
Aluminium
Iron
उत्तर
Nichrome
Explanation-
Nichrome is an alloy used for making wires, while others are soft metals.
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संबंधित प्रश्न
Why does the cord of an electric heater not glow while the heating element does?
Name any two effects of electric current.
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?
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?
Why are the coils of electric irons and electric toasters made of an alloy rather than a pure metal?
A resistance of 25 Ω is connected to a 12 V battery. Calculate the heat energy in joules generated per minute.
Which of the following characteristic is not suitable for a fuse wire?
(a) thin and short
(b) thick and short
(c) low melting point
(d) higher resistance than rest of wiring
If the current flowing through a fixed resistor is halved, the heat produced in it will become:
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.
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).
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.
Rewrite the following statement by selecting the correct option:
1 A = ____________ mA.
What is the heating effect of electric current?
What is a short circuit?
Write two devices based on the heating effect of electric current.
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Explain the importance/uses of fuse wire.
How can overloading be avoided?
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True or False – If False give the correct answer
The fuse wire does not melts whenever there is overload in the wiring.
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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?
Why is parallel arrangement used in domestic wiring?
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Your teacher has shown you the following activity.
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Write down any three questions that come to your mind about this activity
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Explain the working of an electric fuse.
______ wire is used in the filament of the bulbs.
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| 1. | Bulb | a. | Conductor |
| 2. | Electroplating | b. |
Insulator |
| 3. | Pure water | c. | Heating effect of current |
| 4. | Salt solution | d. | Chemical effect of current |
Assertion: A current-carrying wire should be charged.
Reason: The current in a wire is due to the flow of free electrons in a definite direction.
Name the effect of the current responsible for the glow of the bulb in an electrical circuit.
Name a few appliances which work on the basis of the heating effect of current.
What is a trip switch?
A trip switch is a ______ safety device.
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| 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?
In which of the following applications of Iron, rusting will occur most? Support your answer with valid reason.
| A | B | C | D |
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