Question

An electric circuit consisting of a 0.5 m long nichrome wire XY, an ammeter, a voltmeter, four cells of 1.5 V each and a plug key was set up.  

Following graph was plotted between V and I values: 

 

What would be the values of `V/I` rations when the potential difference is 0.8 V, 1.2 V and 1.6 V respectively?
What conclusion do you draw from these values?
 
What is the resistance of the wire? 

Answer 1

When potential difference = 0.8 V, current = 0.32 A.
    `V/I=0.8/0.32` 

    `V/I = 2.5`
     When potential difference = 1.2 V, current = 4.8 A.
    `V/I= 12/48` 

    `V/I=2.5` 

When/ /potential difference = 1.6 V, current = 6.4 A.
    `V/I= 1.6/6.4 `

    `V/I =2.5`h V-I graph is a straight line with a constant slope of 2.5.
The resistance of the wire is 2.5 Ω.