A closely wound solenoid of 2000 turns and area of cross-section 1.5 x 10⁻⁴ m² carries

⇦

⇨

A closely wound solenoid of 2000 turns and area of cross-section 1.5 x 10⁻⁴ m² carries a current of 2.0 A. It suspended through its centre and perpendicular to its length, allowing it to turn in a horizontal plane in a uniform magnetic field 5 x 10⁻² tesla making an angle of 30with the axis of the solenoid. The torque on the solenoid will be:

Options

(a) 3 x 10⁻² N-m
(b) 3 x 10⁻³ N-m
(c) 1.5 x 10⁻³ N-m
(d) 1.5 x 10⁻² N-m

Correct Answer:

1.5 x 10⁻² N-m

Explanation:

Torque on the solenoid is given by ? = MB sin θ
where θ is the angle between the magnetic field and the axis of solenoid. M = niA
? = niA B sin 30⁰
= 2000 x 2 x 1.5 x 10⁻⁴ x 5 x 10⁻² x 1/2
= 1.5 x 10⁻² N – m

Related Questions:

1. A wire of resistance 4 ohm is stretched to twice its original length.
2. The resistance of a carbon resistor of colour code Red-Red Green Silver is(in kΩ)
3. Two thin dielectric slabs of dielectric constants K₁ and K₂, (K₁ < K₂) are inserted
4. If t₁ ̷ ₂ is the half-life of a substance, then t₃ ̷ ₄ is the time in which
5. A particle falls towards earth from infinity. Its velocity on reaching the earth

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