A battery of e.m.f 3.0V is connected across a potentiomet...
A battery of e.m.f 3.0V is connected across a potentiometer wire AB of length 10Ωm−1 as illustrated in the diagram above. If the jockey J makes contact at the 30cm mark, determine the resistance of length AJ and voltage across AJ.
3.0Ω; 0.9V
3.0Ω; 3.0V
3.3Ω; 0.3V
3.3Ω; 9.0V
Correct answer is A
E = 3.0V; Rl=10Ωm−1
l = 30cm = 0.3m; R = 10Ωm−1×0.3m=3Ω
EV=l1l2⟹3V=10.3
= 3×0.31=0.9V