Investigate Current and Magnetic Fields - Physics

Right-hand grip rule. Thumb along current, fingers curl around wire showing field lines.

$B=\frac{\mu_0 I}{2\pi r}$. Field decreases with distance from wire, proportional to current.

tesla (T). Named after Nikola Tesla; 1 T = 1 Wb/m² = 1 N/(A·m).

Concentric circles around the wire. Thumb points along current, fingers curl in field direction.

$B=\mu_0 n I$. Field strength depends on turn density and current, not length.

When $\theta=90^\circ$ (wire perpendicular to $B$). $\sin 90° = 1$ gives maximum force magnitude.

Nearly uniform, along the solenoid axis. Field lines are parallel inside, negligible outside ideal solenoid.

It halves, since $B\propto\frac{1}{r}$. Field follows inverse relationship with radial distance.

Along the loop axis, given by the right-hand rule. Fingers follow current, thumb points through loop center.

The field magnitude doubles. Field is directly proportional to current: $B \propto I$.

$F=0.12\ \text{N}$. Using $F=qvB\sin 90°=2.0×10^{-6}×3.0×10^5×0.20×1$.

$F=0.60\ \text{N}$. Using $F=BIL\sin 90°=0.30×4.0×0.50×1$.

$B=\frac{\mu_0 I}{2R}$. Field at center inversely proportional to loop radius.

$F=BIL\sin\theta$. $\theta$ is angle between current and field directions.

$F=qvB\sin\theta$. Lorentz force law; $\theta$ is angle between velocity and field.

Fleming’s left-hand rule. First finger: field, second: current, thumb: force direction.

Perpendicular to both $\vec{v}$ and $\vec{B}$. Use right-hand rule: fingers $\vec{v}$ to $\vec{B}$, thumb shows force.

$B=1.0\times10^{-5}\ \text{T}$. Using $B=\frac{\mu_0 I}{2\pi r}=\frac{4\pi×10^{-7}×10}{2\pi×0.20}$.

They repel each other. Opposite currents create repulsive magnetic forces.

They attract each other. Same-direction currents create attractive magnetic forces.

$\vec{B}$ points right (clockwise around the wire). Right-hand rule: thumb in, fingers curl clockwise.

$B=\frac{\mu_0 I}{2R}$. Field at loop center is half that of straight wire at same distance.

$F=0\ \text{N}$. $\sin(0°) = 0$, so no force when wire parallel to field.

$F=0.30\ \text{N}$. $F = 0.50 \times 2.0 \times 0.30 \times \sin(90°) = 0.30$ N.

$\vec{B}$ points upward (counterclockwise around the wire). Right-hand rule: thumb out, fingers curl counterclockwise.

Closer field lines indicate a stronger $B$. Field line density represents field magnitude visually.

Direction of the force on a north pole (or compass north end) at that point. Field lines show path a free north pole would follow.

Along the solenoid axis, from its south end to its north end inside. Field lines run straight through the solenoid's interior.

$B=\mu_0 n I$. Uniform field inside; $n$ is turns per unit length.