A sheet is placed on a horizontal surface in front of a strong magnetic pole. A force is needed to :
A. hold the sheet there if it is magnetic.
B. hold the sheet there if it is non-magnetic.
C. move the sheet away from the pole with uniform velocity if it is conducting.
D. move the sheet away from the pole with uniform velocity if it is both, non-conducting and non-polar.
Choose the correct statement(s) from the options given below :
A. hold the sheet there if it is magnetic.
B. hold the sheet there if it is non-magnetic.
C. move the sheet away from the pole with uniform velocity if it is conducting.
D. move the sheet away from the pole with uniform velocity if it is both, non-conducting and non-polar.
Choose the correct statement(s) from the options given below :
- B and D only
- A and C only
A, C and D only
- C only
The Correct Option is B
Approach Solution - 1
A sheet is placed on a horizontal surface in front of a strong magnetic pole. A force is needed to:
A. hold the sheet there if it is magnetic.
B. hold the sheet there if it is non-magnetic.
C. move the sheet away from the pole with uniform velocity if it is conducting.
D. move the sheet away from the pole with uniform velocity if it is both, non-conducting and non-polar.
Choose the correct statement(s) from the options given below:
Explanation:
A. Correct. A magnetic sheet will be attracted to the magnetic pole, requiring a force to hold it in place.
B. Incorrect. A non-magnetic sheet will not be attracted to the magnetic pole, so no force is needed to hold it in place.
C. Correct. If the sheet is conducting and moved away from the pole, changing magnetic flux will induce eddy currents, creating a force opposing the motion.
D. Incorrect. A non-conducting and non-polar sheet will not have induced eddy currents and will not be affected by the magnetic field significantly, requiring no force to move it with uniform velocity.
Conclusion:
The correct statements are A and C.
Approach Solution -2
Step 1: Analyze Statement A
If the sheet is magnetic, the magnetic force due to the strong magnetic pole can pull it towards the pole. A force is required to hold the sheet stationary.
Thus, Statement A is correct.
Step 2: Analyze Statement B
If the sheet is non-magnetic, it experiences no magnetic interaction. No force is needed to hold it.
Thus, Statement B is incorrect.
Step 3: Analyze Statement C
If the sheet is conducting, eddy currents are induced when it moves relative to the magnetic pole. These currents produce opposing forces due to Lenz’s law, requiring a force to move it with uniform velocity.
Thus, Statement C is correct.
Step 4: Analyze Statement D
If the sheet is non-conducting and non-polar, it experiences no magnetic interaction. No force is needed to move it.
Thus, Statement D is incorrect.
Step 5: Conclusion
The correct statements are A and C.
Top Questions on Magnetic Field
- Find the magnetic field at a point 5 cm away from a long straight wire carrying current \( I = 20\,A \).
- Consider a long thin conducting wire carrying a uniform current \( I \). A particle having mass \( M \) and charge \( q \) is released at a distance \( a \) from the wire with a speed \( v_0 \) along the direction of current in the wire. The particle gets attracted to the wire due to magnetic force. The particle turns round when it is at distance \( x \) from the wire. The value of \( x \) is:
- JEE Main - 2025
- Physics
- Magnetic Field
- A charged particle with charge \( q \) and velocity \( \vec{v} \) moves perpendicular to a magnetic field \( \vec{B} \). The radius of the circular path is \( r \). What is the expression for \( r \)?
- CUET (UG) - 2025
- Physics
- Magnetic Field
- A bar magnet has total length \( 2l = 20 \) units and the field point \( P \) is at a distance \( d = 10 \) units from the centre of the magnet. If the relative uncertainty of length measurement is 1%, then the uncertainty of the magnetic field at point P is:
- JEE Main - 2025
- Physics
- Magnetic Field
- A square loop of side 2 m lies in the Y-Z plane in a region having a magnetic field \(\mathbf{B} = (5 \hat{i} - 3 \hat{j} - 4 \hat{k}) \, \text{T}\). The magnitude of magnetic flux through the square loop is
- KCET - 2025
- Physics
- Magnetic Field
Questions Asked in NEET exam
- Consider the diameter of a spherical object being measured with the help of a Vernier Callipers. Suppose its 10 Vernier Scale Divisions (V.S.D.) are equal to its 9 Main Scale Divisions (M.S.D.). The least count in the M.S. is 0.1 cm and the zero of V.S. is at -0.1 cm when the jaws of Vernier callipers are closed. If the main scale reading for the diameter is \(M = 5\) cm and the number of coinciding vernier division is 8, the measured diameter after zero error correction, is:
- NEET (UG) - 2025
- Measurement of length
- A container has two chambers of volumes \(V_1 = 2\) litres and \(V_2 = 3\) litres separated by a partition made of a thermal insulator. The chambers contain \(n_1 = 2\) moles and \(n_2 = 3\) moles of ideal gas at pressures \(p_1 = 1\) atm and \(p_2 = 2\) atm, respectively. When the partition is removed, the mixture attains an equilibrium pressure of :
- NEET (UG) - 2025
- Ideal Gases
A sphere of radius R is cut from a larger solid sphere of radius 2R as shown in the figure. The ratio of the moment of inertia of the smaller sphere to that of the rest part of the sphere about the Y-axis is :
- NEET (UG) - 2025
- Moment Of Inertia
The current passing through the battery in the given circuit, is:
- NEET (UG) - 2025
- Current electricity
A bob of heavy mass \(m\) is suspended by a light string of length \(l\). The bob is given a horizontal velocity \(v_0\) as shown in figure. If the string gets slack at some point P making an angle \( \theta \) from the horizontal, the ratio of the speed \(v\) of the bob at point P to its initial speed \(v_0\) is :
- NEET (UG) - 2025
- Pendulums