The current in a wire can be calculated using the formula:

I = J * A

where:
I is the current,
J is the current density, and
A is the cross-sectional area of the wire.

The cross-sectional area of a wire can be calculated using the formula for the area of a circle:

A = πr²

where:
A is the area, and
r is the radius of the wire.

Given:
J = 2.8 × 10^7 A/m²
r = 0.15 mm = 0.15 * 10^-3 m (since 1 mm = 10^-3 m)

We can first calculate the cross-sectional area of the wire:

A = π * (0.15 * 10^-3 m)² = 0.0000707 m²

Then, we can calculate the current:

I = J * A = 2.8 × 10^7 A/m² * 0.0000707 m² = 1.98 A

So, the current in the wire is approximately 2.0 A. Therefore, the correct answer is B. 2.0 A.

Question

The current in a wire can be calculated using the formula:

I = J * A

where:
I is the current,
J is the current density, and
A is the cross-sectional area of the wire.

The cross-sectional area of a wire can be calculated using the formula for the area of a circle:

A = πr²

where:
A is the area, and
r is the radius of the wire.

Given:
J = 2.8 × 10^7 A/m²
r = 0.15 mm = 0.15 * 10^-3 m (since 1 mm = 10^-3 m)

We can first calculate the cross-sectional area of the wire:

A = π * (0.15 * 10^-3 m)² = 0.0000707 m²

Then, we can calculate the current:

I = J * A = 2.8 × 10^7 A/m² * 0.0000707 m² = 1.98 A

So, the current in the wire is approximately 2.0 A. Therefore, the correct answer is B. 2.0 A.

Knowee AI · Accepted Answer