CBSE Class 12 · 2010 · All India · Magnetic Effects of CurrentVery Short Answer

A beam of protons projected along the

+ x

-axis experiences a force due to a magnetic field along the

- y

-axis. What is the direction of the magnetic field?

Answer: Along the $+ Z$ -axis.

Solution

For positive protons,

F = q (v \times B)

with

v

along

+ x

and

F

along

- y

. A field along

+ z

gives

\overset{x}{^} \times \overset{z}{^} = - \overset{y}{^}

, so

B

points along the

+ Z

-axis.

CBSE Class 12 Board · 2010 · All India · Subjective