A copper bus bar measuring 3/16" by 1 1/2" carries approximately how many amps at a current density of 1000 A/in^2?

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Multiple Choice

A copper bus bar measuring 3/16" by 1 1/2" carries approximately how many amps at a current density of 1000 A/in^2?

Explanation:
The current a conductor can carry at a given current density is found by multiplying its cross‑sectional area by the current density. The bus bar’s cross‑section is 3/16" by 1 1/2", which is (3/16) × (3/2) = 9/32 ≈ 0.28125 in^2. At 1000 A per square inch, the current is 0.28125 × 1000 ≈ 281 A, i.e., about 280 A. So 280 A is the correct approximate rating. In practice, actual current capacity can vary with temperature rise and cooling, but this calculation gives the approximate value.

The current a conductor can carry at a given current density is found by multiplying its cross‑sectional area by the current density. The bus bar’s cross‑section is 3/16" by 1 1/2", which is (3/16) × (3/2) = 9/32 ≈ 0.28125 in^2. At 1000 A per square inch, the current is 0.28125 × 1000 ≈ 281 A, i.e., about 280 A. So 280 A is the correct approximate rating. In practice, actual current capacity can vary with temperature rise and cooling, but this calculation gives the approximate value.

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