TS EAMCET · Physics · Magnetic Effects of Current
A magnetic needle lying parallel to a magnetic field is turned through \(60^{\circ}\). The work done on it is \(W\). The torque required to maintain the magnetic needle in the position mentioned above is
- A \(\sqrt{3} W\)
- B \(\frac{\sqrt{3}}{2} W\)
- C \(\frac{W}{2}\)
- D \(2 W\)
Answer & Solution
Correct Answer
(A) \(\sqrt{3} W\)
Step-by-step Solution
Detailed explanation
Work done \(\begin{aligned} W & =M B\left(1-\cos 60^{\circ}\right) \\ & =\frac{M B}{2}\end{aligned}\) The torque required to maintain the magnetic needle…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- A wheel of radius \(0.4 \mathrm{~m}\) can rotate freely about its axis as shown in the figure. A string is wrapped over its rim and a mass of \(4 \mathrm{~kg}\) is hung. An angular acceleration of 8 rad- \(\mathrm{s}^{-2}\) is produced in it due to the torque. Then, moment of inertia of the wheel is \(\left(g=10 \mathrm{~ms}^{-2}\right)\)TS EAMCET 2009 Easy
- The speed of a transverse wave on a string is \(160 \mathrm{~m} / \mathrm{s}\). If the three resonant frequencies of this string respectively are \(160 \mathrm{~Hz}, 240 \mathrm{~Hz}\) and \(400 \mathrm{~Hz}\), the length of the string isTS EAMCET 2018 Medium
- In an optical fibre, core and cladding were made with materials of refractive indices 1.5 and 1.414 respectively. To observe total internal reflection, what will be the range of incident angle with the axis of optical fibre?TS EAMCET 2010 Medium
- A wave is represented by the equation The minimum distance between the two particles always having the same speed is. (Assume and are in SI units)TS EAMCET 2021 Medium
- A particle moves along a straight line such that its displacement ' \(x\) ' varies with time ' \(t\) ' as \(x=\alpha t^3+\beta t^2+\gamma\), where \(\alpha, \beta, \gamma\) are constants. \(V_1\) is the average velocity of the particle during its journey between \(t=1 \mathrm{~s}\) and \(t=3 \mathrm{~s} . \mathrm{V}_2\) is the instantaneous velocity of the particle at \(t=3 \mathrm{~s}\). The ratio \(\frac{\mathrm{V}_1}{\mathrm{~V}_2}\) isTS EAMCET 2022 Easy
- A man slides down on a telegraphic pole with an acceleration equal to one-fourth of acceleration due to gravity. The frictional force between man and pole is equal to in terms of man's weight \(w\)TS EAMCET 2007 Easy
More PYQs from TS EAMCET
- The path difference between two particles of a sound wave is 50 cm and the phase difference between them is \(1.8 \pi\). If the speed of sound in air is \(340 \mathrm{~ms}^{-1}\), the frequency of the sound wave isTS EAMCET 2024 Easy
- A Cassegrain telescope uses two mirrors of radii of curvature 25 cm and 16 cm separated by a distance of 2.5 cm. The position of the final image of an object at infinity isTS EAMCET 2025 Medium
- In an \(n\)-type semiconductor, the fermi energy level liesTS EAMCET 2007 Easy
- If the distances of the object and its real image from the principal focus of a concave mirror are 16 cm and 9 cm respectively, then the focal length of the mirror isTS EAMCET 2025 Medium
- A printed page is kept pressed by a transparent cube of edge \(t\). The refractive index of the cube varies as \(\mu(z)=1+\frac{z}{t}\), where \(z\) is the vertical distance from bottom of the cube. If viewed from top, then the printed letters appear to be shifted by an amountTS EAMCET 2018 Medium
- A person wearing a parachute jumps off a plane from a height of 2 km from the ground and falls freely for 20 m before his parachute opens. After his parachute opens if he continues to move uniformly with the velocity attained due to his freefall, the total time taken by the person to reach the ground is
(Acceleration due to gravity \(=10 \mathrm{~ms}^{-2}\) )TS EAMCET 2025 Medium