In a mass spectrometer used for measuring the masses of ions, the ions

⇦

⇨

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:

1. Two sound waves of wavelengths 5m and 6m formed 30 beats in 3 seconds
2. For a cubic crystal structure which one of the following relations
3. Mass and diameter of a ring is 2 kg and 1 m respectively. The moment of inertia
4. A spring balance is attched to the ceiling of lift.A man hangs his bag on the string
5. A particle starting from the origin (0, 0) moves in a straight line in the (x, y) 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