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Why do we cover plug pin holes which are within the reach of children with cellotape or a plastic cover when not in use?

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प्रश्न

Why do we cover plug pin holes which are within the reach of children with cellotape or a plastic cover when not in use?

लघु उत्तरीय
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उत्तर

The child may put his/her fingers into the socket and he/she may get an electric shock which could be fatal. Plastic/cellotape is a bad conductor of electricity and hence chances of electric shock get reduced.

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अध्याय 14: Electric Current and Its Effects - SHORT ANSWER QUESTIONS [पृष्ठ ७८]

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एनसीईआरटी एक्झांप्लर Science [English] Class 7
अध्याय 14 Electric Current and Its Effects
SHORT ANSWER QUESTIONS | Q 15. | पृष्ठ ७८

संबंधित प्रश्न

When the current is switched on through a wire, a compass needle kept nearby gets deflected from its north-south position. Explain.


Do you think an electromagnet can be used for separating plastic bags from a garbage heap? Explain.


Write the correct option by observing the figures.


In the Activity shown below, how do we think the displacement of rod AB will be affected if

  1. current in rod AB is increased
  2. a stronger horse-shoe magnet is used
  3. length of the rod AB is increased?
  • Take a small aluminium rod AB (of about 5 cm). Using two connecting wires suspend it horizontally from a stand, as shown in Fig.
  • Place a strong horse-shoe magnet in such a way that the rod lies between the two poles with the magnetic field directed upwards. For this put the north pole of the magnet vertically below and south pole vertically above the aluminium rod (Fig.).
  • Connect the aluminium rod in series with a battery, a key and a rheostat.
  • Now pass a current through the aluminium rod from end B to end A.
  • What do you observe? It is observed that the rod is displaced towards the left. You will notice that the rod gets displaced.
  • Reverse the direction of current flowing through the rod and observe the direction of its displacement. It is now towards the right.
  • Why does the rod get displaced?


A current-carrying rod, AB, experiences a force perpendicular to its length and the magnetic field. Support for the magnet is not shown here, for simplicity.


When the resistance of a conductor increases, the current ____________ .

(ii) Global warming is a desirable aspect of the intensified greenhouse effect.


Answer the following question:
State the effect on the magnetic needle in Oersted’s experiment when:  
(a) the current is passed through the wire.  
(b) the current through the wire is increased
(c) the current through the wire is reversed. 


Read the given passage and answer the following questions:

The home electrical connection consists of ‘live’, ‘neutral’ and ‘earth’ wires. The ‘live’ and the ‘neutral’ wires have potential difference of 220 V. The ‘earth’ is connected to ground. Due to a fault in the equipment or if the plastic coating on the ‘live’ and the ‘neutral’ wires gives a way the two wires come in contact with each other and a large current flows through it producing heat. If any inflammable material (such as wood, cloth, plastic, etc.) exists around that place it can catch fire. Therefore a fuse wire is used as a precautionary measure.

  1. Name the two wires having potential difference of 220 V.
  2. What is a short circuit?
  3. Write the function of a fuse.

A soft iron bar is introduced inside the current-carrying solenoid. The magnetic field inside the solenoid ____________.


What do you mean by the magnetic effect?


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