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प्रश्न
How can overloading be avoided?
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उत्तर
Overloading in the electric circuit can be avoided by not connecting many electric appliances at a time in the circuit.
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संबंधित प्रश्न
State four most common electrical appliances based on heating effect of electric current. Why do we use finely heated platinum wire in surgery?
Why does the cord of an electric heater not glow while the heating element does?
Why is the tungsten used almost exclusively for filament of electric lamps?
The safety device based on the heating effect of electric current is called a ______.
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?
How does the resistance of a wire vary with its:
diameter?
Why does the connecting cord of an electric heater not glow hot while the heating element does?
The current passing through a room heater has been halved. What will happen to the heat produced by it?
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
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?
Three heaters each rated 250 W, 100 V are connected in parallel to a 100 V supply. Calculate:
- the total current taken from the supply
- the resistance of each heater and
- the energy supplied in kWh to the three heaters in 5 hours.
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.
Answer the following question:
what is the heating effect of the electric current? state any four applications of it?
In an electric bulb, coil of _______ metal is used.
The electricity bill specifies the usage in _______.
What is the heating effect of electric current?
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.
Explain the application of heating effect of electric current in an electric bulb with a diagram.
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.
A fuse wire repeatedly gets burnt when used with a good heater. It is advised to use a fuse wire of:
An electric bulb is connected to a 220 V generator. The current is 0.50 A. What is the power of the bulb?
How does use of a fuse wire protect electrical appliances?
An electric cell produces electricity from the ______ ______ in it.
Your teacher has shown you the following activity.
Activity: Teacher has wound a long insulated piece of wire around an iron nail in the form of a coil. Free ends of the wire are connected to a cell through a switch as shown in the following figure. The current is switched on and some pins are placed near the ends of the nail.
Write down any three questions that come to your mind about this activity.
An electric fuse has a body made of ceramic and two points for connecting the fuse wire.
Match the following
| 1. | Bulb | a. | Conductor |
| 2. | Electroplating | b. |
Insulator |
| 3. | Pure water | c. | Heating effect of current |
| 4. | Salt solution | d. | Chemical effect of current |
Name the effect of the current responsible for the glow of the bulb in an electrical circuit.
Define the following:
Electrolyte
An electric kettle of 2 kW is used for 2h. Calculate the energy consumed in
- kilowatt hour and
- joules.
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?
