Question

An electron is moving along positive x-axis. A uniform electric field exists towards negative y-axis. What should be the direction of magnetic field of suitable magnitude so that net force on electron is zero?

• A. Positive z-axis
• B. Negative z-axis
• C. Positive y-axis
• D. Negative y-axis

Answer 1

Answer: (B)

Negative z-axis

Answer 2

= – ( $\overrightarrow { \mathrm { V } }$ × $\vec { B }$ )