Target Exam

CUET

Subject

Physics

Chapter

Moving Charges and Magnetism

Question:

A charged particle moves along a circular path in a uniform magnetic field of 0.04 T with a velocity of $2 × 10^5\, m/s$. The charge to mass ratio of the particle is $5 × 10^7\, C/kg$. The radius of the circular path of the charged particle is

Options:

1000 cm

10 cm

50 cm

100 cm

Correct Answer:

10 cm

Explanation:

The correct answer is Option (2) → 10 cm

Magnetic field $B = 0.04 \, \text{T}$

Velocity $v = 2 \times 10^5 \, \text{m/s}$

Charge to mass ratio $\frac{q}{m} = 5 \times 10^7 \, \text{C/kg}$

Radius of circular path: $r = \frac{mv}{qB} = \frac{v}{\left(\frac{q}{m}\right)B}$

$r = \frac{2 \times 10^5}{(5 \times 10^7)(0.04)}$

$r = \frac{2 \times 10^5}{2 \times 10^6} = 0.1 \, \text{m}$

Final Answer: $0.1 \, \text{m}$