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

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Solution

before length id doubled
I=V/R=5A
when Length is doubled resistance also get doubled.
R is directly proportional to length.
so when resistance get doubled
after length is doubled
I'=V/2R
I'=I/2
I'=2.5A

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

before length id doubledI=V/R=5Awhen Length is doubled resistance also get doubled.R is directly proportional to length.so when resistance get doubledafter length is doubledI'=V/2RI'=I/2I'=2.5A

before length id doubled
I=V/R=5A
when Length is doubled resistance also get doubled.
R is directly proportional to length.
so when resistance get doubled
after length is doubled
I'=V/2R
I'=I/2
I'=2.5A