⇦ | ![]() | ⇨ |
In a mass spectrometer used for measuring the masses of ions, the ions are initially accelerated by an electric potential V and then made to describe semicircular path of radius R using a magnetic field B. If V and B are kept constant, the ratio ( charge on the ion / mass of the ion) will be proportional to
Options
(a) 1/R²
(b) R²
(c) R
(d) 1/R
Correct Answer:
1/R²
Explanation:
In mass spectrometer, when ions are accelerated through potential V
1/2 mv² = qV …..(i)
As the magnetic field curves the path of the ions in a semiciruclar orbit
Bqv = mv² / R v = BqR / m ….(ii)
Substituting (ii) and (i)
1/2 m[ BqR / m]² = qv or q/m = 2V / B²R²
Since V and B are constants, q/m ∞ 1/R²
Related Questions:
- The respective speeds of the molecules are 1,2,3,4 and 5 km/s.
- In photoelectric effect, the photoelectric current
- A body is thrown vertically upward in air when air resistance is taken into account
- When the angle of incidence is 60° on the surface of a glass slab, it is found
- A compass needle which is allowed to move in a horizontal plane
Topics: Magnetic Effects of Current and Magnetism
(167)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
18000+ students are using NEETLab to improve their score. What about you?
Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.
Share this page with your friends
Leave a Reply