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प्रश्न
A coil of an alloy _______ is used in electric heater cooker as a resistor.
पर्याय
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
An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.
An electric heater of resistance 8 Ω draws 15 A from the service mains 2 hours. Calculate the rate at which heat is developed in the heater.
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?
Name any two effects of electric current.
The safety device based on the heating effect of electric current is called a ______.
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 room heater draws a current of 2.4 A from the 120 V supply line. What current will this room heater draw when connected to 240 V supply line?
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?
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?
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
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?
Which electric heating device in your home do you think have resistors which control the flow of electricity?
Compute the heat generated while transferring 96000 coulombs of charge in two hours through a potential difference of 40 V.
Which of the following substance contracts on heating?
What is overloading?
Live wire and neutral wires have a 220 V potential difference.
Write scientific reason.
A coil made up of alloy Nichrome is used in the electric heater cooker as a resistor.
When does overloading occur?
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.
The heating element of an electric iron is made up of:
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 component used as a safety device is electric circuit is ______.
When a switch is in OFF position,
- circuit starting from the positive terminal of the cell stops at the switch.
- circuit is open.
- no current flows through it.
- current flows after some time.
Choose the combination of correct answer from the following.
Unscramble the following words:
SFEU
Can we use the same fuse in a geyser and a television set? Explain.
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.
What is a trip switch?
A trip switch is a ______ safety device.
In the electric equipment producing heat like iron, electric heater, boiler, toaster etc., an alloy such as nichrome is used, not pure metals.
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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In a set up the students coated iron nails with zinc metal and noted that, iron nails coated with zinc prevents rusting. They also observed that zinc initially acts as a physical barrier, but an extra advantage of using zinc is that it continues to prevent rusting even if the layer of zinc is damaged. Name this process of rust prevention and give any two other methods to prevent rusting.
