# Current Electricity Exe-9B Long Ans Concise Physics ICSE Class 9 Selina Publishers

Current Electricity Exe-9B Long Ans Concise Physics ICSE Class 9 Selina Publishers There is the solutions of Long Answer type Questions of your latest textbook which is applicable in 2024-25 academic sessionVisit official Website CISCE for detail information about ICSE Board Class-9 current electricity syllabus.

## Current Electricity Exe-9B Long Answer Type

Concise Physics ICSE Class 9 Selina Publishers

 Board ICSE Class 9 Subject Physics Writer / Publication Concise selina Publishers Chapter-9 Current Electricity Exe-9B Potential Differance and Resistance Topics Solution of Exe-9(B) Long Answer Type Academic Session 2024-2025

### Potential Difference And Resistance

Current Electricity Exe-9B Long Ans Concise Physics ICSE Class 9 Selina Publishers

Page – 221

##### Question-1 Explain the concept of electric potential difference in terms of work done in transferring the charge.

Answer-1 We know that, like charges repel and unlike charges attract, therefore to create an excess or deficit of electrons at a point, some work is to be done in moving the charges (or electrons) against the forces between them. The force between the two charges is zero when they are at infinite separation.

Hence, quantitatively, potential at a point is measured in terms of work done in bringing a charge q from infinity to that point. If work W’ is done in bringing a charge q from infinity to a point, then potential at that point is:

V=W′/q​

Hence, the potential difference between two conductors is measured in terms of work done in transferring the charge from one conductor to the other, through a metallic wire. Potential difference is a scalar quantity.

##### Question-2 Explain why does a metal wire when connected to a cell offer resistance to the flow of current.

Answer-2 Current flows in a wire due to the flow of electrons in an opposite direction. Now there are some positively charged particles too. So when electrons flow from the negative electrode to the positive electrode through the metal wire.

During their movement, they collide with free electrons and fixed ions of the wire. This causes them to lose their speed and change their direction. As a result, electrons slow down and drift towards the positive terminal. This is called resistance.

##### Question-3 State three factors on which the resistance of a wire depends. Explain how does the resistance depend on the factors stated by you.

Answer-3 Resistance of a wire depends upon:

1=>Length of wire: Resistance is directly proportional to the length of a wire.
2=>Area of a cross-section of wire: Resistance is inversely proportional to the area of cross-section the wire.
3=>The temperature of the wire: Resistance of a wire is directly proportional to the temperature of the wire.

—:  end of Current Electricity Exe-9B Long Ans Concise Physics ICSE Class 9 Selina Publishers  :—

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