Using the relationship between electric charge, time, and current, find the electric current in amperes when a total charge of 500 coulombs flows through a conductor in 25 seconds.

Introduction / Context:
Electric current is a basic concept in electricity and electronics. It describes how much electric charge flows past a point in a circuit per unit time. This question tests your ability to apply the simple formula relating charge, time, and current. Being comfortable with this relationship is essential for solving many introductory problems in physics and electrical engineering.

Given Data / Assumptions:

• Total electric charge, Q = 500 coulombs.
• Time taken for this charge to flow, t = 25 seconds.
• The circuit is assumed to be steady so that current can be treated as constant over this time interval.
• We are asked to find current I in amperes.

Concept / Approach:
The definition of electric current is the rate at which charge flows. Mathematically, this is written as I = Q / t, where I is the current in amperes, Q is the charge in coulombs, and t is the time in seconds. One ampere is defined as one coulomb of charge passing through a cross section of a conductor in one second. By substituting the given values of charge and time into this formula, we can directly calculate the current.

Step-by-Step Solution:
Step 1: Write the formula for current: I = Q / t. Step 2: Substitute Q = 500 coulombs and t = 25 seconds into the formula. Step 3: Compute I = 500 / 25. Step 4: Perform the division: 500 / 25 = 20. Step 5: Therefore, the current I = 20 amperes.

Verification / Alternative check:
We can quickly check the reasonableness of the result. If 25 seconds correspond to 500 coulombs, then in 1 second the charge flow is 500 / 25 = 20 coulombs per second. Since 1 ampere is 1 coulomb per second, 20 coulombs per second corresponds to 20 amperes. The units match and the arithmetic is straightforward, confirming that the value is correct.

Why Other Options Are Wrong:

• 12500 A: This would correspond to an extremely large current and would arise from incorrectly multiplying rather than dividing the values.
• 40 A: This suggests a miscalculation, possibly using 500 / 12.5 or another incorrect combination of numbers.
• 6250 A: This again is unrealistically high and would result from a major arithmetic or formula error, such as using I = Q * t instead of I = Q / t.

Common Pitfalls:
Students sometimes confuse the formula and use I = t / Q or mistakenly multiply charge and time. Another common mistake is mishandling units, such as mixing coulombs with milli-coulombs or seconds with minutes without converting. Always remember that current in amperes is charge in coulombs divided by time in seconds. Keeping track of units is a powerful way to catch errors before finalising the answer.

Final Answer:
The electric current flowing is 20 A.