Answer:
3.53 V
Explanation:
Electric charge: The is the rate of flow of electric charge along a conductor.
The S.I unit of electric charge is C.
Mathematically it is expressed as,
Q = It ............................ Equation 1
Where Q = electric charge, I = current, t = time.
I = Q/t.......................... Equation 2
From the question, charge flows through the conductor at the rate of 420 C/mim
Which means in 1 min, 420 C of charge flows through the conductor.
Hence,
Q = 420 C, t = 1 min = 60 seconds
Substitute into equation 2
I = 420/60
I =7 A
Also
P = VI......................... Equation 3
Where P = power, V = potential drop, I = current.
V = P/I................... Equation 4
Note: Power = Energy/time
From the question, P = 742/30 = 24.733 W. and I = 7 A.
Substitute these values into equation 4
V = 24.733/7
V = 3.53 V
Hence the potential drop across the conductor = 3.53 V
