# Moving Charges and Magnetism Class 12 Physics Important Questions

Please refer to Moving Charges and Magnetism Class 12 Physics Important Questions with solutions provided below. These questions and answers have been provided for Class 12 Physics based on the latest syllabus and examination guidelines issued by CBSE, NCERT, and KVS. Students should learn these problem solutions as it will help them to gain more marks in examinations. We have provided Important Questions for Class 12 Physics for all chapters in your book. These Board exam questions have been designed by expert teachers of Standard 12.

## Class 12 Physics Important Questions Moving Charges and Magnetism

Case Based Questions :

Read the paragraph given below and choose the correct alternative for questions given after paragraph:
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-tocharge ratio of ions. In a typical MS procedure, a sample, which may be solid, liquid, or gaseous, is ionized, for example by bombarding it with a beam of electrons HAVING SAME KINETIC ENERGY.
This may cause some of the sample’s molecules to break up into positively charged fragments or simply become positively charged without fragmenting. These ions (fragments) are then separated according to their mass-to-charge ratio, for example by accelerating them and subjecting them to an electric or magnetic field: ions of the same mass-to-charge ratio will undergo the same amount of deflection. The ions are detected by a mechanism capable of detecting charged particles, such as an electron multiplier. Results are displayed as spectra of the signal intensity of detected ions as a function of the mass-tocharge ratio. The atoms or molecules in the sample can be identified by correlating known masses (e.g., an entire molecule) to the identified masses or through a characteristic fragmentation pattern.

Question. If magnetic force experienced by the charged particle is perpendicular to the velocity of the particle, then work done is:
(a) Zero
(b) Maximum
(c) Minimum
(d) None of these

A

Question. When a charged particle enters a magnetic field at some angle, then which of the following forces provide necessary centripetal force for its motion.
(a) Lorentz force
(b) Magnetic force
(c) electric field
(d) gravitational force

B

Question. A particle is subjected in a region where crossed electric field and magnetic field are present. The particles with velocity v=E/B, will go at an angle of
(a) 90o to the initial direction of motion
(b) 0o to the initial direction of motion
(c) 180o to the initial direction of motion
(d) 45o to the initial direction of motion