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प्रश्न
A coil of an alloy _______ is used in electric heater cooker as a resistor.
विकल्प
Stainless steel
Nichrome
Copper
Bronze
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उत्तर
A coil of an alloy nichrome is used in electric heater cooker as a resistor.
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संबंधित प्रश्न
Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.
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 ______.
Why are the coils of electric irons and electric toasters made of an alloy rather than a pure metal?
Why does the connecting cord of an electric heater not glow hot while the heating element does?
Explain why, tungsten is used for making the filaments of electric bulbs.
Name the material which is used for making the filaments of an electric bulb.
An electric fuse works on the:
(a) chemical effect of current
(b) magnetic effect of current
(c) lighting effect of current
(d) heating effect of current
The elements of electrical heating devices are usually made of:
(a) tungsten
(b) bronze
(c) nichrome
(d) argon
Give a scientific reason.
Tungsten metal is used to make a solenoid type coil in an electric bulb.
Give a scientific reason:
For electric power transmission, copper or aluminium wire is used.
Give Scientific reason.
In practice, the unit kWh is used for the measurement of electrical energy, rather than joule.
Name the factors on which the heat produced in a wire depends when current is passed in it, and state how does it depend on the factors stated by you.
Write two devices based on the heating effect of electric current.
Right or wrong sentence.
Live wire and neutral wires have a 220 V potential difference.
When does overloading occur?
Name some devices that run using heat effect of electric current
Explain the heating effect of electric current.
Name any two appliances which work under the principle of heating effect of current.
The heating element of an electric iron is made up of:
Which of the following gases are filled in electric bulbs?
What is Joule’s heating effect? How can it be demonstrated experimentally? List its four applications in daily life.
An electric cell produces electricity from the ______ ______ in it.
Name two electric devices for each where
- heating effect of current is used and
- magnetic effect of current is used.
An MCB can be used instead of a fuse in an electrical circuit.
Explain the working of an electric fuse.
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.
Fuse is a strip of alloy wire which is made up of lead and tin with a very low ______.
An electrochemical cell converts ______ energy into ______ energy.
Define the following:
Electrolyte
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.
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?
Anannya responded to the question: Why do electrical appliances with metallic bodies are connected to the mains through a three-pin plug, whereas an electric bulb can be connected with a two-pin plug?
She wrote: Three-pin connections reduce heating of connecting wires.
- Is her answer correct or incorrect? Justify.
- What is the function of a fuse in a domestic circuit?
When a current I flows through a wire of resistance R for time t then the electrical energy produced is given by ______.
The graph of voltage vs current for four different materials is shown below.
Which of these four materials would be used for making filament of bulb?
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.
