Formula for current flowing through a wire is I = 6t2 + 4t – 2 here t is in second and I is an ampere. In this wire, what is the quantity of electric charge passing in time interval 1 sec to 2 sec?
(A) 8C
(B) 18C
(C) 20C
(D) 24C
The correct option (B) 18C
Explanation:
I = 6t2 + 4t – 2
∴ ɸ = ∫2 I ∙ dt
∴ ɸ = 2∫1 (6t2 + 4t – 2)
= [6 × (t3/3) + {4t2/2} – 2t]12
= [2t3. + 2t2 – 2t]12
= 2[t3 + t2 – 1]12
= 2[(8 + 4 – 2) – (1 + 1 – 1)]
= 2[10 – 1] = 18C
