Question

Which of the following particles will deviate $(<\pi /2)$ maximum and when they enter magnetic field region perpendicularly with same velocity and travels same distance:

• A. $Be$
• B. Proton
• C. $\alpha -$particle
• D. $Li++$

Answer 1

Answer: (D)

$Li++$

Given: Each particle has same magnetic field and same velocity.

Solution: As we know the formula of radius of orbit of moving particle in magnetic field:

$R=\frac{mv}{qB}$

Ratio $\frac{m}{q}$ is constant

Whose radius is maximum will have least deflection,

By applying this rule we get to know that ,Li${}^{2+}$ has minimum value of$\frac{m}{q}$ so maximum value of deflection.

Hence the correct option is D