Question

Direct focussing is obtained by deflecting the ion beam along a _________ trajectory through the magnetic field.

(a) 120^o

(b) 150^o

(c) 190^o

(d) 180^o

I have been asked this question in an online interview.

My doubt is from Magnetic Deflection Mass Spectrometer in section Mass Spectrometer of Analytical Instrumentation

Answer 1

Correct choice is (d) 180^o

Explanation: Direct focussing is obtained by deflecting the ion beam along a 180^o trajectory through a magnetic field. The gap between the poles must be large enough to contain the ion source.