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Define magnetic field strength (B).
The magnitude of the magnetic field at a point in space, measured in Teslas (T).
What is the permeability of free space ($\mu_0$)?
A physical constant that relates the amount of current to the strength of the magnetic field produced; $\mu_0 = 4\pi × 10^{-7} T⋅m/A$.
Define current (I).
The rate of flow of electric charge, measured in Amperes (A).
Define the term 'external magnetic field'.
A magnetic field generated by a source separate from the current-carrying wire being considered.
Define the magnetic force ($F_B$).
The force exerted on a current-carrying wire when it is placed in a magnetic field, measured in Newtons (N).
What is the effect of increasing the current in a wire on the magnetic field around it?
Increasing the current increases the strength of the magnetic field (directly proportional).
What is the effect of increasing the distance from a current-carrying wire on the magnetic field strength?
Increasing the distance decreases the strength of the magnetic field (inversely proportional).
What happens when a current-carrying wire is placed parallel to a magnetic field?
The magnetic force on the wire is zero because $\sin(0) = 0$ in the formula $F_{B}=I \ell B \sin \theta$.
What is the effect of the angle between the current and the magnetic field on the force experienced by the wire?
The force is maximum when the angle is 90 degrees (perpendicular) and zero when the angle is 0 or 180 degrees (parallel or anti-parallel).
What is the effect of two parallel wires carrying current in the same direction?
The wires experience an attractive force towards each other.
What is the effect of two parallel wires carrying current in the opposite direction?
The wires experience a repulsive force away from each other.
What are the steps to determine the direction of the magnetic field around a current-carrying wire?
1. Use Right-Hand Rule #1 (RHR1). 2. Point your thumb in the direction of the conventional current. 3. Your fingers will curl in the direction of the magnetic field.
What are the steps to calculate the magnetic force on a wire in a magnetic field?
1. Identify the current (I), length ($\ell$), magnetic field (B), and angle ($\theta$). 2. Use the formula $F_{B}=I \ell B \sin \theta$. 3. Calculate the magnitude of the force. 4. Use RHR2 to determine the direction of the force.
What are the steps to find the net magnetic field due to multiple current-carrying wires?
1. Calculate the magnetic field due to each wire individually. 2. Determine the direction of each magnetic field. 3. Add the magnetic fields as vectors to find the net magnetic field.
What are the steps to determine the direction of the magnetic force on a current-carrying wire in a magnetic field?
1. Use Right-Hand Rule #2 (RHR2). 2. Point your fingers in the direction of the current. 3. Orient your palm to face the direction of the magnetic field. 4. Your extended thumb will point in the direction of the magnetic force.
What are the steps to calculate the magnetic field strength near a long, straight wire?
1. Identify the current (I) and the distance (r) from the wire. 2. Use the formula $B=\frac{\mu_{0}}{2 \pi} \frac{I}{r}$. 3. Plug in the values and calculate B.