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प्रश्न
Rewrite the following statement by selecting the correct option:
1 A = ____________ mA.
विकल्प
102
10-2
103
10-3
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उत्तर
1 A = `10^3` mA.
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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?
When current is switched ‘on’ in a room heater, it ______.
The safety device based on the heating effect of electric current is called a ______.
An electric kettle rated at 220 V, 2.2 kW, works for 3 hours. Find the energy consumed and the current drawn.
Write down the formula for the heat produced when a current I is passed through a resistor R for time t.
The current passing through a room heater has been halved. What will happen to the heat produced by it?
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 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
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.
Identify the figure and give its use.

Identify the figure and give its use.

Solve the following example.
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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.
Why does tungsten metal used to make solenoid type coil in an electric bulb?
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Write the mathematical expression for Joule’s law of heating.
What is the heating effect of electric current?
Write scientific reason.
A coil made up of alloy Nichrome is used in the electric heater cooker as a resistor.
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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
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Define fuse.
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Mark the correct choice
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- 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.
Name two electric devices for each where
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- magnetic effect of current is used.
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.
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.
______ wire is used in the filament of the bulbs.
Copper wire offers very little ______ and does not get heated up quickly.
Name a few appliances which work on the basis of the heating effect of current.
An electric fuse is a wire made up of a material having ______ melting point.
A fuse is used in an electric circuit to stop high currents flowing through the circuit.
The electric fuse works on the Joule heating principle.
Tara, after completing her exams, went to her grandmother's house along with her younger brother Rahul. One day, Rahul came home after playing and switched on the fan and air conditioner. At the same time, his grandmother was preparing a milkshake for him using a mixer. Suddenly, they heard a big sound and the electricity of the house got shut down. Tara is called an electrician. He said the main reason for supply to shut down was overloading.
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- How can the effects of overloading be avoided?
Find the odd one out.
