Question

A narrow beam of protons and deuterons, each having the same momentum, enters a region of uniform magnetic field directed perpendicular to their direction of momentum. The ratio of the radii of the circular paths described by them is:

• A. \(1:2\)
• B. \(1:1\)
• C. \(2:1\)
• D. \(1:3\)

Hint:

In magnetic field motion, radius depends on momentum, not mass separately.

Answer 1

The Correct Option is B

Step 1: Radius of circular path in magnetic field: \[ r = \frac{p}{qB} \]
Step 2: Protons and deuterons have same momentum and same charge.
Step 3: Hence, their radii are equal.