Magnetic Field — MCQ Practice

An electron moves with a velocity $\vec{v} = (2\hat{i} + 3\hat{j});\text{m/s}$ in a uniform magnetic field $\vec{B} = (4\hat{i} + 2\hat{j});\text{T}$. What is the magnetic force experienced by the electron? (Charge of electron $e = -1.6 \times 10^{-19};\text{C}$)

An infinitely long straight conductor carries a current of $5\,\text{A}$. What is the magnitude of the magnetic field at a perpendicular distance of $10\,\text{cm}$ from the conductor? (Take $\mu_0 = 4\pi \times 10^{-7};\text{T}\cdot\text{m/A}$)

A circular coil of radius $R$ carrying current $I$ produces a magnetic field $B_0$ at its center. If the current is doubled and the radius is halved, what will be the new magnetic field at the center?

Which of the following statements about magnetic field lines is INCORRECT?

A long solenoid has 1000 turns per meter and carries a current of $2\,\text{A}$. What is the magnetic field inside the solenoid? (Take $\mu_0 = 4\pi \times 10^{-7};\text{T}\cdot\text{m/A}$)

A proton enters a uniform magnetic field of $0.5\,\text{T}$ with a velocity of $3 \times 10^6\,\text{m/s}$ perpendicular to the field. What is the radius of the circular path followed by the proton? (Mass of proton $m_p = 1.67 \times 10^{-27},\text{kg}$, Charge of proton $e = 1.6 \times 10^{-19},\text{C}$)