Question

If a net charge \( Q \) flows across any cross-section of a conductor in time \( t \), then the current \( I \) through the cross-section is

• A. \( I = \frac{Q}{t} \)
• B. \( I = \frac{t}{Q} \)
• C. \( I = \frac{t^2}{Q} \)
• D. \( I = \frac{Q^2}{t} \)

Hint:

Remember the fundamental definition of electric current: it's the rate at which charge flows. The unit of current is Ampere (A), where 1 Ampere is equal to 1 Coulomb per second (1 C/s).

Answer 1

The Correct Option is A

Step 1: Recall the definition of electric current.
Electric current \( I \) is defined as the rate of flow of electric charge \( Q \) through a conductor. It is the amount of charge that passes through a given cross-sectional area per unit time. Step 2: Express the definition mathematically.
The mathematical expression for electric current is given by: \[ I = \frac{\Delta Q}{\Delta t} \] where \( \Delta Q \) is the amount of charge that flows through the cross-section and \( \Delta t \) is the time taken for this charge to flow. Step 3: Apply the given variables.
In this question, the net charge that flows is given as \( Q \), and the time taken is given as \( t \). Therefore, substituting these into the formula for current, we get: \[ I = \frac{Q}{t} \]