Advertisements
Advertisements
प्रश्न
When does overloading occur?
Advertisements
उत्तर
Overloading occurs, when more appliances work together in a circuit.
APPEARS IN
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?
An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.
How does the resistance of a wire vary with its area of cross-section?
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?
Write down the formula for the heat produced when a current I is passed through a resistor R for time t.
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 by passing an electric current through a fixed resistor is proportional to the square of:
(a) magnitude of resistance of the resistor
(b) temperature of the resistor
(c) magnitude of current
(d) time for which current is passed
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
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
An electric iron is connected to the mains power supply of 220 V. When the electric iron is adjusted at 'minimum heating' it consumes a power of 360 W but at 'maximum heating' it takes a power of 840 W. Calculate the current and resistance 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.
Give a scientific reason:
For electric power transmission, copper or aluminium wire is used.
Name the factors on which the heat produced in a wire depends when current is passed in it, and state how does it depend on the factors stated by you.
These days when current in the circuit suddenly increases _______ switches are used.
Find the odd one out and give its explanation.
What is the heating effect of electric current?
What is a short circuit?
What is overloading?
Right or wrong sentence.
Live wire and neutral wires have a 220 V potential difference.
Explain the application of heating effect of electric current in an electric bulb with a diagram.
Define fuse.
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:
An electric bulb is connected to a 220 V generator. The current is 0.50 A. What is the power of the bulb?
Why is parallel arrangement used in domestic wiring?
(a) Observe the diagram given below and state whether the bulb will glow or not when we switch on K.

(b) Is it safe to handle the bulb when the switch is OFF?
(c) Give a reason for your answer in (b).
An electric component used as a safety device is electric circuit is ______.
Name two electric devices for each where
- heating effect of current is used and
- magnetic effect of current is used.
What is an electric fuse made up of?
Copper wire offers very little ______ and does not get heated up quickly.
Name the effect of the current responsible for the glow of the bulb in an electrical circuit.
What is a trip switch?
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?
An electric iron of resistance 20 Ω draws a current of 5 A. The heat developed in the iron in 30 seconds is ______.
The graph of voltage vs current for four different materials is shown below.

Which of these four materials would be used for making filament of bulb?
An electric iron is rated 220 V, 2 kW. If the iron is used for 3h daily find the cost of running it for one week if it costs ₹ 4.25 per kWh.
