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प्रश्न
What is a short circuit?
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उत्तर
Due to a fault in the equipment or if the plastic coating on the ‘live’ and the ‘neutral’ wires gives away the two wires come in contact with each other and a large current flows through it producing heat. This is known as short circuit.
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संबंधित प्रश्न
Give two reasons why nichrome alloy is used for making the heating elements of electrical appliances.
How does the resistance of a wire vary with its:
diameter?
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Derive the expression for the heat produced due to a current 'I' flowing for a time interval 't' through a resistor 'R' having a potential difference 'V' across its ends. With which name is this relation known?
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How does the wire in the filament of a light bulb behave differently to the other wires in the circuit when the current flows?
What property of the filament wire accounts for this difference?
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.
Give a scientific reason:
For electric power transmission, copper or aluminium wire is used.
Identify the figure and give its use.

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.
Rewrite the following statement by selecting the correct option:
1 A = ____________ mA.
Write the mathematical expression for Joule’s law of heating.
Compute the heat generated while transferring 96000 coulombs of charge in two hours through a potential difference of 40 V.
The ‘live’ and the ‘neutral’ wires have potential difference of _______.
In an electric bulb, coil of _______ metal is used.
The electricity bill specifies the usage in _______.
Which of the following substance contracts on heating?
How can overloading be avoided?
Name any two appliances which work under the principle of heating effect of current.
Mark the correct choice
- Assertion: Electric appliances with a metallic body have three wire connections.
- Reason: Three-pin connections reduce the heating of the connecting wires.
An electric iron draws a current of 4 A when connected to 220 V mains. Its resistance must be:
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Tara, after completing her exams, went to her grandmother's house along with her younger brother Rahul. One day, Rahul came home after playing and switched on the fan and air conditioner. At the same time, his grandmother was preparing a milkshake for him using a mixer. Suddenly, they heard a big sound and the electricity of the house got shut down. Tara is called an electrician. He said the main reason for supply to shut down was overloading.
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- How can the effects of overloading be avoided?
An electric kettle consumes 1 kW of electric power when operated at 220 V. A fuse wire of what rating must be used for it?
An electric iron is rated 220 V, 2 kW. If the iron is used for 3h daily find the cost of running it for one week if it costs ₹ 4.25 per kWh.
