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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
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.
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?
What is nichrome? State its one use.
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?
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?
How much heat will an instrument of 12 W produce in one minute if it is connected to the heat produced by it?
The heat produced in a wire of resistance 'x' when a current 'y' flows through it in time 'z' is given by:
(a) x2 × y × z
(b) x × z × y2
(c) y × z2 × x
(d) y × z × x
If the current flowing through a fixed resistor is halved, the heat produced in it will become:
The electrical resistivities of four materials P, Q, R and S are given below:
| P | `6.84xx10^8`Ωm |
| Q | `1.70xx10^8`Ωm |
| R | ` 1.0xx10^15`Ωm |
| s | `11.0xx10^-7`Ωm |
Which material will you use for making: (a) heating element of electric iron (b) connecting wires of electric iron (c) covering of connecting wires? Give reason for your choice in each case.
Which electric heating device in your home do you think have resistors which control the flow of electricity?
Give a scientific reason.
Tungsten metal is used to make a solenoid type coil in an electric bulb.
Identify the figure and give its use.
Solve the following example.
Two tungsten bulbs of wattage 100 W and 60 W power work on 220 V potential difference. If they are connected in parallel, how much current will flow in the main conductor?
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).
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.
Answer the following question:
what is the heating effect of the electric current? state any four applications of it?
Write the mathematical expression for Joule’s law of heating.
The ‘live’ and the ‘neutral’ wires have potential difference of _______.
What is the heating effect of electric current?
Which metal is used to make the filament of an electric bulb?
What is used to turn off the sudden increase in current in the electrical circuit of the house nowadays?
Name any two appliances which work under the principle of heating effect of current.
Which of the following gases are filled in electric bulbs?
Why is parallel arrangement used in domestic wiring?
Can we use the same fuse in a geyser and a television set? Explain.
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.
______ wire is used in the filament of the bulbs.
Fuse is a strip of alloy wire which is made up of lead and tin with a very low ______.
The following is not a safety device.
The electric fuse works on the Joule heating principle.
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.
What is the heating effect of electric current?
