Quick current calculation: When 12 V is applied to a 68 Ω resistor, what current flows (choose the closest value)?

Introduction / Context:This item reinforces the current form of Ohm’s law, I = V / R, widely used in initial circuit checks and resistor sizing. Correct unit handling ensures that milliampere ranges are interpreted properly.

Given Data / Assumptions:

• Applied voltage V = 12 V.
• Resistance R = 68 Ω.
• Ideal linear resistor assumption; temperature and tolerance effects ignored.

Concept / Approach:Compute I from I = V / R and convert amperes to milliamperes for comparison with the choices. Retain three significant digits during division, then round to match the nearest listed value.

Step-by-Step Solution:

Verification / Alternative check:Back compute voltage: V ≈ I * R ≈ 0.176 * 68 ≈ 11.97 V, which matches the given 12 V within rounding, confirming the selection is correct.

Why Other Options Are Wrong:

• 816 mA: Would require R ≈ 12 / 0.816 ≈ 14.7 Ω, not 68 Ω.
• 17.6 mA: Ten times too small compared with the correct value.
• 8.16 mA: Off by roughly a factor of 20.

Common Pitfalls:

• Dropping digits during division and misplacing the decimal when converting to mA.
• Confusing 68 Ω with 680 Ω due to similar digits.

Final Answer:176 mA