Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • NCERT
  • What is electrical resistivity? In a series electrical circuit comprising a resistor made up of a metallic wire, the ammeter reads 5 A. The reading of the ammeter decreases to half when the length of the wire is doubled. Why?

What is electrical resistivity? In a series electrical circuit comprising a resistor made up of a metallic wire, the ammeter reads 5 A. The reading of the ammeter decreases to half when the length of the wire is doubled. Why?

Answers (1)

Electrical Resistivity it is the constant of proportionality for each material which gives the resistance of a resistor when multiplied with length and divided with the area of cross section of the resistor.
V=IR\\ R=p\frac{l}{A}

Where l is the length and A is the area of cross section

ρ  is called the electrical resistivity of the material of the conductor.

The SI unit of resistivity is W-m. The resistivity of a material varies with temperature.

When the length of the wire is doubled the current in the circuits gets halved. The resistance is doubled which in turn halves the current for the same voltage.

 

Posted by

infoexpert24

View full answer

Similar Questions

Latest Question