Question:
A magnet makes 40 oscillation per minute at a place having magnetic intensity of $0.1 \times 10^{-5}$ tesla. At another place it takes 2.5 sec to complete one oscillation. The value of earth's horizontal field at that place is
A magnet makes 40 oscillation per minute at a place having magnetic intensity of $0.1 \times 10^{-5}$ tesla. At another place it takes 2.5 sec to complete one oscillation. The value of earth's horizontal field at that place is
Updated On: Jun 23, 2023
- $0.76 \times 10^{-6} $ tesla
- $0.18 \times 10^{-6} $ tesla
- $0.09 \times 10^{-6} $ tesla
- $0.36 \times 10^{-6} $ tesla
Hide Solution
Verified By Collegedunia
The Correct Option is D
Solution and Explanation
Time period of vibration of a magnet is $T = 2 \pi \sqrt{\frac{I}{MH}}$
For the same magnet, I and M are constant where M = magnetic moment,
I = moment of inertia of magnet.
$\Rightarrow \, T \propto \frac{1}{\sqrt{H}}$
First case
$T_{1} = \frac{60}{40} = \frac{3}{2}= 1.5 \sec. $
$ H_{1} = 0.1 \times10^{-5} T , T_{2} = 2.5 \sec, H_{2} = ?$
$ \Rightarrow \frac{1.5}{2.5} = \sqrt{\frac{H_{2}}{H_{1}}} $
$\Rightarrow \frac{15}{25} = \sqrt{\frac{H_{2}}{10^{-6}}}$
$ \Rightarrow H_{2} = \left(\frac{3}{5}\right)^{2} \times10^{-6}$
$ \Rightarrow H_{2} = \frac{9}{25} \times10^{-6} = 0.36 \times10^{-6} T $
Was this answer helpful?
0
0
Top Questions on Magnetism and matter
- A coil of 60 turns and area \( 1.5 \times 10^{-3} \, \text{m}^2 \) carrying a current of 2 A lies in a vertical plane. It experiences a torque of 0.12 Nm when placed in a uniform horizontal magnetic field. The torque acting on the coil changes to 0.05 Nm after the coil is rotated about its diameter by 90°. Find the magnitude of the magnetic field.
- CBSE CLASS XII - 2025
- Physics
- Magnetism and matter
- A current-carrying loop can be considered as a magnetic dipole placed along its axis. Explain.
- CBSE CLASS XII - 2025
- Physics
- Magnetism and matter
- Differentiate between magnetic flux through an area and magnetic field at a point.
- CBSE CLASS XII - 2025
- Physics
- Magnetism and matter
- A bar magnet is held with its length along the axis of a closed coil. Initially, the south pole of the magnet faces the coil. If the magnet is moved towards the coil, explain how a current is induced in the coil and in what direction.
- CBSE CLASS XII - 2025
- Physics
- Magnetism and matter
- A charged particle \(q\) moving with a velocity \( \mathbf{v} \) is subjected to a uniform magnetic field \( \mathbf{B} \) acting perpendicular to \( \mathbf{v} \). If a uniform electric field \( \mathbf{E} \) is also set up in the region along the direction of \( \mathbf{B} \), describe the path followed by the particle and draw its shape.
- CBSE CLASS XII - 2025
- Physics
- Magnetism and matter
View More Questions
Concepts Used:
Magnetism & Matter
Magnets are used in many devices like electric bells, telephones, radio, loudspeakers, motors, fans, screwdrivers, lifting heavy iron loads, super-fast trains, especially in foreign countries, refrigerators, etc.
Magnetite is the world’s first magnet. This is also called a natural magnet. Though magnets occur naturally, we can also impart magnetic properties to a substance. It would be an artificial magnet in that case.
Read More: Magnetism and Matter
Some of the properties of the magnetic field lines are:
- The lines and continuous and outside the magnet, the field lines originate from the North pole and terminate at the South pole
- They form closed loops traversing inside the magnet.
- But here the lines seem to originate from the South pole and terminate at the North pole to form closed loops.
- More number of close lines indicate a stronger magnetic field
- The lines do not intersect each other
- The tangent drawn at the field line gives the direction of the field at that point.