Advertisements
Advertisements
प्रश्न
Write scientific reason.
A coil made up of alloy Nichrome is used in the electric heater cooker as a resistor.
Advertisements
उत्तर
- The electric heater-cooker works on the principle of heating effect of electric current.
- Alloys (such as nichrome) as compared to metals have higher resistivity.
- Unlike metals they can be heated to higher temperature.
Hence, a coil made up of alloy nichrome is used in the electric heater-cooker as a resistor.
APPEARS IN
संबंधित प्रश्न
Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.
An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.
Why is the tungsten used almost exclusively for filament of electric lamps?
Why are the conductors of electric heating devices, such as bread-toasters and electric irons, made of an alloy rather than a pure metal?
When current is switched ‘on’ in a room heater, it ______.
The safety device based on the heating effect of electric current is called a ______.
What is nichrome? State its one use.
Explain why, tungsten is used for making the filaments of electric bulbs.
Explain why, the current that makes the heater element very hot, only slightly warms the connecting wires leading to the heater.
A resistance of 25 Ω is connected to a 12 V battery. Calculate the heat energy in joules generated per minute.
The elements of electrical heating devices are usually made of:
(a) tungsten
(b) bronze
(c) nichrome
(d) argon
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?
An electric iron is connected to the mains power supply of 220 V. When the electric iron is adjusted at ‘minimum heating' it consumes a power of 360 W but at 'maximum heating’ it takes a power of 840 W. Calculate the current and resistance in each case.
Give a scientific reason.
Tungsten metal is used to make a solenoid type coil in an electric bulb.
Give Scientific reasons.
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.
A coil of an alloy _______ is used in electric heater cooker as a resistor.
Right or wrong sentence.
Live wire and neutral wires have a 220 V potential difference.
Explain the application of heating effect of electric current in an electric bulb with a diagram.
True or False – If False give the correct answer
The fuse wire does not melts whenever there is overload in the wiring.
Define fuse.
Name some devices that run using heat effect of electric current
A fuse wire repeatedly gets burnt when used with a good heater. It is advised to use a fuse wire of:
Which of the following gases are filled in electric bulbs?
B1, B2 and B3 are three identical bulbs connected as shown in Figure. When all the three bulbs glow, a current of 3A is recorded by the ammeter A.
- What happens to the glow of the other two bulbs when the bulb B1 gets fused?
- What happens to the reading of A1, A2, A3 and A when the bulb B2 gets fused?
- How much power is dissipated in the circuit when all the three bulbs glow together?
An electric component used as a safety device is electric circuit is ______.
An electric cell produces electricity from the ______ ______ in it.
Can we use the same fuse in a geyser and a television set? Explain.
An electric fuse has a body made of ceramic and two points for connecting the fuse wire.
It would cost a man Rs. 3.50 to buy 1.0 kW h of electrical energy from the Main Electricity Board. His generator has a maximum power of 2.0 kW. The generator produces energy at this maximum power for 3 hours. Calculate how much it would cost to buy the same amount of energy from the Main Electricity Board.
A student boils water in an electric kettle for 20 minutes. Using the same mains supply he wants to reduce the boiling time of water. To do so should he increase or decrease the length of the heating element? Justify your answer.
An electrochemical cell converts ______ energy into ______ energy.
Find the odd one out.
1 kWh is equal to ______.
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 iron of resistance 20 Ω draws a current of 5 A. The heat developed in the iron in 30 seconds is ______.
