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. The horizontal range and maximum height of a projectile are equal.The angle of projection
2. Force required to move a mass of 1kg at rest on a horizontal rough plane
3. A wheel is rotating at 900 rpm about its axis.When the power is cut-off it
4. The molecular weight of a gas is 44. The volume occupied by 2.2 g of this gas
5. A step down transformer is used on a 1000 V line to deliver 20 A at 120 V

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