Question

the filament of a bulb takes a current 0.1 a when potential difference across it is 0.2 v when the potential difference across it becomes 1.0v the current become 0.4 a calculate the resistance of filament in each case and account for the difference

Answer 1

I = 0.1A
v = 0.2v
v = IR
0.2/0.1 =R
R = 2ohm
second condition
V =1v
I = 0.4A
v = ir
1/0.4 = R
R =2.5ohm