Based on a current density of 1000 amps per square inch, a copper bus bar measuring 3/16" x 1 1/2" would carry a current of?

Based on a current density of 1000 amps per square inch, a copper bus bar measuring 3/16" x 1 1/2" would carry a current of?

• A. 1000 amps
• B. 560 amps
• C. 320 amps
• D. 280 amps

Answer: (D)

Current-carrying capability comes from multiplying the current density by the conductor’s cross-sectional area. The cross-section is the width times the thickness, so for this bus bar: 3/16 inch × 1 1/2 inch equals 0.1875 in × 1.5 in = 0.28125 in². Multiply by the current density: 1000 A/in² × 0.28125 in² ≈ 281 amps. Rounding to the nearest practical value, the closest option is 280 amps.

Current-carrying capability comes from multiplying the current density by the conductor’s cross-sectional area. The cross-section is the width times the thickness, so for this bus bar: 3/16 inch × 1 1/2 inch equals 0.1875 in × 1.5 in = 0.28125 in². Multiply by the current density: 1000 A/in² × 0.28125 in² ≈ 281 amps. Rounding to the nearest practical value, the closest option is 280 amps.