If a long straight wire carries a current I, what is the magnetic field B at a d
Practice Questions
Q1
If a long straight wire carries a current I, what is the magnetic field B at a distance r from the wire according to the Biot-Savart Law?
B = (μ₀I)/(2πr)
B = (μ₀I)/(4πr²)
B = (μ₀I)/(r)
B = (μ₀I)/(2r)
Questions & Step-by-Step Solutions
If a long straight wire carries a current I, what is the magnetic field B at a distance r from the wire according to the Biot-Savart Law?
Correct Answer: B = (μ₀I)/(2πr)
Step 1: Understand that a long straight wire carrying current creates a magnetic field around it.
Step 2: Identify the variables: I is the current in the wire, r is the distance from the wire, and μ₀ is a constant called the permeability of free space.
Step 3: Recall the formula for the magnetic field B around a long straight wire: B = (μ₀I)/(2πr).
Step 4: Recognize that this formula shows how the magnetic field B depends on the current I and the distance r from the wire.
Step 5: Use the formula to calculate the magnetic field B if you know the values of I and r.
Biot-Savart Law – The Biot-Savart Law describes how electric currents produce magnetic fields, specifically how the magnetic field varies with distance from a current-carrying wire.
Magnetic Field Calculation – Understanding how to calculate the magnetic field around a long straight wire using the formula B = (μ₀I)/(2πr).
Distance Dependence – Recognizing that the magnetic field strength decreases with increasing distance from the wire.
