electricity

A

I = total emf / total resistance

I = 3e / 4R

I’ = (e+e-e) / 4R

I’ = e / 4R

I’ = 1/3 I

D

C

if temperature is constant, resistance is constant

P = I²R so P is directly proportional to I²

P is never negative as I² is always positive

D

A

Z) P = V²/R

X) P = (V/2)²/R = V²/4R

B

as R decreases, total resistance decreases

if R decreases, v (across R) decreases

if R decreases, I increases