⇦ | ⇨ |
A magnetic needle suspended parallel to a magnetic field requires √3 J of work to turn it through 60⁰. The torque needed to maintain the needle in this position will be:
Options
(a) 2 √3 J
(b) 3 J
(c) √3 J
(d) 3/2 J
Correct Answer:
3 J
Explanation:
According to work energy theorem
W = U final – U initial = MB (cos 0 – cos 60⁰)
W = MB/2 = √3J …(i)
? = M⃗ x B⃗ = MB sin 60⁰ = (MB √3 / 2) …(ii)
From eq (i) and (ii)
? = 2 √3 x √3 / 2 = 3 J
Related Questions: - A long straight wire of radius a carries a steady current I. The current is uniformly
- In a common emitter (CE) amplifier having a voltage gain G, the transistor
- A body of mass m slides down an incline and reaches the bottom
- The refractive index of water, glass and diamond are 1.33, 1.50, 2.40 respectively
- A particle of mass M is suited at the centre of a spherical shell of same mass and radius
Topics: Magnetic Effects of Current and Magnetism
(167)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- A long straight wire of radius a carries a steady current I. The current is uniformly
- In a common emitter (CE) amplifier having a voltage gain G, the transistor
- A body of mass m slides down an incline and reaches the bottom
- The refractive index of water, glass and diamond are 1.33, 1.50, 2.40 respectively
- A particle of mass M is suited at the centre of a spherical shell of same mass and radius
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