The current flowing through a wire as a function fo time is given as: I = 3t² + 2t + 5 The charge flowing through any cross-section of the wire in first 2 s is:
Correct Answer :
22 C
Solution :
The correct option is 22 C.
To find the total charge flowing through any cross-section of the wire, we use the relationship between electric current and electric charge. Electric current is defined as the rate of flow of charge with respect to time:
This equation can be rearranged to express the small amount of charge, , that flows in an infinitesimal time interval, :
To determine the total charge that flows through the wire in the first 2 seconds (from to ), we integrate both sides of the equation over this time range:
We are given the current as a function of time: . Substituting this expression into our integral, we get:
We now integrate each term individually with respect to :
Simplifying the coefficients gives:
Now, evaluate the antiderivative at the upper limit of integration (2) and subtract the value at the lower limit (0):
Therefore, the charge flowing through any cross-section of the wire in the first 2 seconds is 22 C.
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