Question

If magnetic field is along +ve z-axis and a potential difference is applied across an ionized gas chamber placed in the x-y plane then : (i) Magnetic force on +ve ions will act along +y axis (ii) Magnetic force on electrons will act along + y axis

• A. Both (i) and (ii) are correct
• B. Both (i) and (ii) are wrong
• C. Only (i) is correct
• D. Only (ii) is correct

Answer 1

Answer: (B)

Both (i) and (ii) are wrong

Answer 2

Force on + ve ions= q (v × B)

= q(v × B) =q vB (–)

Force on – ve electrons = – q (v × B)

= –q(v (– $\hat { \mathbf { i } }$ ) × B)= q vB (–)