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प्रश्न
Name safety measures commonly used in electric circuits and appliances.
Name two safety measures commonly used in electric circuits and appliances.
उत्तर १
Following safety measures should be followed while using electricity :
- Wires carrying electricity should not be touched bare footed.
- While working with electricity, one must wear gloves made up of insulated material and rubber sole shoes.
- The insulation of the wire must be checked periodically.
- The electrical appliances must be earthed.
- The electric circuits should be switched off during lighting.
- An electric fuse is a very safety device. Electric fuse of proper rating should be used to stop the flow of excess electric current and to solve save the electrical appliances.
- For avoiding overloading, many appliances should not be connected at a time in the circuit.
उत्तर २
- Fuses: Fuses protect circuits from excessive current flow. When the current crosses a safe threshold, the fuse wire melts and prevents the circuit, avoiding further harm.
- Circuit Breaker: Circuit breakers use an electromagnet or bimetallic strip to open the circuit when excessive current flows through it.
Notes
Students should refer to the answer according to their questions and provided marks.
संबंधित प्रश्न
When does short circuiting take place?
What happens to the flow of electric current during a short circuit?
How can the effects of overloading be avoided?
Why should the wires carrying electricity not be touched barefooted?
An electric oven of 2 kW is operated in a domestic electric circuit (220 V) that has a current rating of 5 A. What result do you expect? Explain.
What precaution should be taken to avoid the overloading of domestic electric circuits?
At the time of short circuit, the current in the circuit ______.
What is the function of an earth wire?
Draw a circuit diagram to show how a soft iron piece can be transformed into an electromagnet.
Describe how an electromagnet could be used to separate copper from iron in a scrap yard.
What name is given to the device which automatically cuts off the electricity supply during short-circuiting in household wiring?
What is the usual capacity of an electric fuse used (i) in the lighting circuit
Give the symbol of an electric fuse used in circuit diagrams.
List the colours of the three wires in the cable connected to the plug of an electric iron.
What is the electric potential of the wire in a mains supply cable?
When does an electric short circuit occur?
In which wire in a A.C. housing circuit is the switch introduced to operate the lights?
What is the usually colour of the insulation of :
(a) live wire
(b) neutral wire
(c) earth wire?
What is the main propose of earthing an electrical appliance?
Give two reasons why different electrical appliances in a domestics circuit are connected in parallel.
Fill in the following blank with suitable words:
The earth wire should be connected to the ........... of an appliance.
How are the electrical appliances connected in a house circuit: in series or in parallel? Give reason.
State the voltage at which electricity is supplied to our houses.
Answer the following question:
What is overloading? When does it occur? How can overloading be avoided?
A fuse should always be placed in the ____________.
Earth wire carries ____________.
How does an electric fuse prevent the electric circuit and the appliances from a possible damage due to short circuiting or overloading.
Why is it necessary to earth metallic appliances?
