Grade 12 Physics: Magnetic Fields

A current-carrying wire is placed in a magnetic field of \( 0.5 \, \text{T} \) at a right angle. If the wire carries a current of \( 3 \, \text{A} \) and has a length of \( 0.2 \, \text{m} \), calculate the magnetic force on the wire.

A proton moves perpendicular to a magnetic field with a velocity of \( 2 \times 10^6 \, \text{m/s} \) in a field of \( 0.8 \, \text{T} \). Calculate the magnetic force acting on the proton. (Given: charge of proton \( = 1.6 \times 10^{-19} \, \text{C} \))

Calculate the radius of the circular path taken by an electron moving at \( 5 \times 10^5 \, \text{m/s} \) in a magnetic field of \( 0.4 \, \text{T} \). (Given: charge of electron \( = 1.6 \times 10^{-19} \, \text{C} \), mass of electron \( = 9.11 \times 10^{-31} \, \text{kg} \))