Advertisements
Advertisements
प्रश्न
Why are the coils of electric irons and electric toasters made of an alloy rather than a pure metal?
Advertisements
उत्तर
The coils of the heating elements of electric irons and electric toasters are made of alloys like nichrome rather than a pure metal because alloys have a high resistance and a high melting point.
APPEARS IN
संबंधित प्रश्न
Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal?
Give two reasons why nichrome alloy is used for making the heating elements of electrical appliances.
Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?
Write down the formula for the heat produced when a current I is passed through a resistor R for time t.
A heating coil has a resistance of 200 Ω. At what rate will heat be produced in it when a current of 2.5 A flows through it?
Write the mathematical expression for Joule’s law of heating.
In an electric bulb, coil of _______ metal is used.
Live wire and neutral wires have a 220 V potential difference.
Name any two appliances which work under the principle of heating effect of current.
A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross-section of the filament in 16 seconds would be roughly:
An electric cell produces electricity from the ______ ______ in it.
Unscramble the following words:
SFEU
______ wire is used in the filament of the bulbs.
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.
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.
- What is overloading?
- Is overloading and short the same? When does short-circuiting take place?
- How can the effects of overloading be avoided?
In the electric equipment producing heat like iron, electric heater, boiler, toaster etc., an alloy such as nichrome is used, not pure metals.
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?
