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प्रश्न
When does overloading occur?
उत्तर
Overloading occurs, when more appliances work together in a circuit.
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संबंधित प्रश्न
Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.
An electric heater is connected to the 230 V mains supply. A current of 8 A flows through the heater.
(b) How much energy is transferred to the heater each second?
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.
A resistance of 25 Ω is connected to a 12 V battery. Calculate the heat energy in joules generated per minute.
The current passing through a room heater has been halved. What will happen to the heat produced by it?
The current passing through an electric kettle has been doubled. The heat produced will become:
(a) half
(b) double
(c) four time
(d) one-fourth
Which of the following characteristic is not suitable for a fuse wire?
(a) thin and short
(b) thick and short
(c) low melting point
(d) higher resistance than rest of wiring
Give a scientific reason.
Tungsten metal is used to make a solenoid type coil in an electric bulb.
Give a scientific reason.
For electric power transmission, copper or aluminium wire is used.
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.
Identify the figure and give its use.
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).
Why does tungsten metal used to make solenoid type coil in an electric bulb?
Rewrite the following statement by selecting the correct option:
1 A = ____________ mA.
Name any two appliances which works on the phenomenon of heating effect of electric current.
True or False – If False give the correct answer
The fuse wire does not melts whenever there is overload in the wiring.
Name some devices that run using heat effect of electric 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:
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?
Which of the following gases are filled in electric bulbs?
Assertion: Bending of wire decreases the resistance of the electric wire.
Reason: The resistance of a conductor depends on length, thickness, nature of material and temperature of the conductor.
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?
Name two electric devices for each where
(i) the heating effect of current is used and
(ii) the magnetic effect of current is used.
Your teacher has shown you the following activity.
Activity: The teacher has wound a long insulated piece of wire around an iron nail in the form of a coil. The free ends of the wire are connected to a cell through a switch as shown in Figure 14.3. 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
______ 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 electrochemical cell converts ______ energy into ______ energy.
A trip switch is a ______ safety device.
If 220 V potential difference is applied across an electric bulb, a current of 0.45 A flows in the bulb. What must be the power of the bulb?
In the electric equipment producing heat like iron, electric heater, boiler, toaster etc., an alloy such as nichrome is used, not pure metals.
When a current I flows through a wire of resistance R for time t then the electrical energy produced is given by ______.
