Question

2A of current is flowing through a wire of length 1 m. What is the amount of charge passing through it in 1 min?

• A. 120 C
• B. 40 C
• C. 1 C
• D. 2C
• E. 10 C

Hint:

Be careful to identify and ignore extraneous data (like the length of the wire here). Always ensure your time unit is in seconds before multiplying by Amperes to get Coulombs.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Electric current is defined as the rate of flow of electric charge through a cross-section of a conductor over time.
Step 2: Key Formula or Approach:
The relationship between current (\(I\)), total charge (\(Q\)), and time (\(t\)) is:
\[ I = \frac{Q}{t} \implies Q = I \times t \]
Ensure that standard SI units are used: Current in Amperes (A), time in seconds (s), which gives charge in Coulombs (C).
Step 3: Detailed Explanation:
Given values:
Current, \(I = 2\) A
Time, \(t = 1\) minute
First, convert time to seconds:
\(t = 1 \text{ min} = 60 \text{ s}\)
Notice that the length of the wire ("1 m") is extraneous information provided to act as a distractor. It is not needed to calculate total charge passed.
Now, calculate the charge \(Q\):
\[ Q = I \times t \]
\[ Q = 2 \text{ A} \times 60 \text{ s} \]
\[ Q = 120 \text{ C} \]
Step 4: Final Answer:
The amount of charge passing through the wire is 120 Coulombs.