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प्रश्न
Identify the figure and give its use.
Identify a figure and write one use of it:
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उत्तर
- Figure: MCB (Miniature Circuit Breaker)
- Uses: An MCB is a device which functions as a fuse but does not require replacement. MCB falls down to break the circuit when a heavy amount of current flows through it. Once the fault is rectified, the MCB is reset.
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संबंधित प्रश्न
Why does the cord of an electric heater not glow while the heating element does?
An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.
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(b) How much energy is transferred to the heater each second?
Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?
Explain why, the current that makes the heater element very hot, only slightly warms the connecting wires leading to the heater.
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?
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(a) chemical effect of current
(b) magnetic effect of current
(c) lighting effect of current
(d) heating effect of current
Give a scientific reason.
Tungsten metal is used to make a solenoid type coil in an electric bulb.
Give Scientific reason.
In practice, the unit kWh is used for the measurement of electrical energy, rather than joule.
Identify the figure and give its use.
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Write the mathematical expression for Joule’s law of heating.
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In an electric bulb, coil of _______ metal is used.
What is the heating effect of electric current?
What is a short circuit?
Name any two appliances which works on the phenomenon of heating effect of electric current.
True or False – If False give the correct answer
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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.
An electric iron consumes energy at the rate of 420 W when heating is at the maximum rate and 180 W when heating is at the minimum rate. The applied voltage is 220 V. What is the current in each case?
An electric iron draws a current of 4 A when connected to 220 V mains. Its resistance must be:
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Why is parallel arrangement used in domestic wiring?
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Name two electric devices for each where
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