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
A conducting bar moves on two conducting rails as shown in the figure. A constant magnetic field \( B \) exists into the page. The bar starts to move from the vertex at time \( t = 0 \) with a constant velocity. If the induced EMF is \( E \propto t^n \), then the value of \( n \) is _____.
- JEE Main - 2025
- Physics
- Magnetic Field
- 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 solid sphere is rolling without slipping on a horizontal plane. The ratio of the linear kinetic energy of the centre of mass of the sphere and rotational kinetic energy is:
- JEE Main - 2025
- Physics
- Magnetic Field
- The magnetic field inside a 200 turns solenoid of radius 10 cm is \( 2.9 \times 10^{-4} \) Tesla. If the solenoid carries a current of 0.29 A, then the length of the solenoid is:
- JEE Main - 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
Questions Asked in NEET exam
The velocity (v) - time (t) plot of the motion of a body is shown below :
The acceleration (a) - time(t) graph that best suits this motion is :- NEET (UG) - 2024
- speed and velocity
- Match List I with List II
List-I
(Reaction)List-II
(Reagents/Condition)(A) 
(I) 
(B) 
(II) CrO3 (C) 
(III) KMnO4/KOH, \(\Delta\) (D) 
(IV) (i) O3
(ii) Zn-H2O
Choose the correct answer from the options given below:- NEET (UG) - 2024
- Chemical Reactions
- Given below are two statements:
Statement I: Mitochondria and chloroplasts both double membranes bound organelles.
Statement II: Inner membrane of mitochondria is relatively less permeable, as compared chloroplast. I
In the light of the above statements, choose the mis appropriate answer from the options given below- NEET (UG) - 2024
- Cell structure and organelles
- A compound X contains 32% of A, 20% of B and remaining percentage of C. Then, the empirical formula of X is:
(Given atomic masses of A=64; B=40; C=32 u)- NEET (UG) - 2024
- Some basic concepts of chemistry
- The minimum energy required to launch a satellite of mass m from the surface of earth of mass M and radius R in a circular orbit at an altitude of 2R from the surface of the earth is :
- NEET (UG) - 2024
- Escape speed