Q19.A proton and an α - particle (with their masses in the ratio of 1 : 4 and charges in the ratio of 1 : 2 ) are accelerated from rest through a potential difference V . If a uniform magnetic field (B) is set up perpendicular to their velocities, the ratio of the radii rp : rα of the circular paths described by them will be: (1) 1 : 3 (2) 1 : √2 (3) 1 : 2 (4) 1 : √3
What This Question Tests
The question tests the ability to relate kinetic energy gained by charged particles from a potential difference to their momentum, and then use this to find the ratio of radii of their circular paths in a uniform magnetic field.
Concepts Tested
Formulas Used
K = qV
K = p^2 / (2m)
r = mv / (qB) = p / (qB)
📚 NCERT Sections This Tests
4.11 — In A Chamber, A Uniform Magnetic Field Of 6.5 G (1 G = 10–4 T) Is
Physics Class 11 · Chapter 4
4.11 In a chamber, a uniform magnetic field of 6.5 G (1 G = 10–4 T) is maintained. An electron is shot into the field with a speed of 4.8 × 106 m s–1 normal to the field. Explain why the path of the electron is a circle. Determine the radius of the circular orbit. (e = 1.5 × 10–19 C, me = 9.1×10–31 kg)
4.10 — Two Moving Coil Meters, M1 And M2 Have The Following Particulars:
Physics Class 11 · Chapter 4
4.10 Two moving coil meters, M1 and M2 have the following particulars: R1 = 10 Ω, N1 = 30, A1 = 3.6 × 10–3 m2, B1 = 0.25 T R2 = 14 Ω, N2 = 42, A2 = 1.8 × 10–3 m2, B2 = 0.50 T (The spring constants are identical for the two meters). Determine the ratio of (a) current sensitivity and (b) voltage sensitivity of M2 and M1.
4.4 — A Horizontal Overhead Power Line Carries A Current Of 90 A In East To
Physics Class 11 · Chapter 4
4.4 A horizontal overhead power line carries a current of 90 A in east to west direction. What is the magnitude and direction of the magnetic field due to the current 1.5 m below the line?
📋 Question Details
- Chapter
- Magnetic Effects of Current
- Topic
- Motion in Magnetic Field
- Year
- 2019
- Shift
- 12 Jan Shift 1
- Q Number
- Q19
- Type
- MCQ
- NCERT Ref
- Class 12 Physics Ch 4: Moving Charges and Magnetism
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