Magnetic-Effect-Of-Current-And-Magnetism-Quiz-3

Magnetic Effect Of Current And Magnetism Quiz-3

Dear Readers,

As per analysis for previous years, it has been observed that students preparing for NEET find Physics out of all the sections to be complex to handle and the majority of them are not able to comprehend the reason behind it. This problem arises especially because these aspirants appearing for the examination are more inclined to have a keen interest in Biology due to their medical background. 

Furthermore, sections such as Physics are dominantly based on theories, laws, numerical in comparison to a section of Biology which is more of fact-based, life sciences, and includes substantial explanations. By using the table given below, you easily and directly access to the topics and respective links of MCQs. Moreover, to make learning smooth and efficient, all the questions come with their supportive solutions to make utilization of time even more productive. Students will be covered for all their studies as the topics are available from basics to even the most advanced. 

Q21. Two identical short bar magnets, each having magnetic moment of 10 Am², are arranged such that their axial lines are perpendicular to each other and their centres be along the same straight line in a horizontal plane. If the distance between their centres is 0.2 m, the resultant magnetic induction at a point midway between them is (μ₀=4π×10^-7 Hm^-1)

•  √2×10^-7 tesla
•  √5×10^-7 tesla
•  √2×10^-3 tesla
•  √5×10^-3 tesla

Solution
                          

Q22.Relative permeability of iron is 5500, then it magnetic susceptibility will be

•  5500×10⁷
•  5500×10^-7
•  5501
•  5499

Solution
                            

Q23.  A very small magnet is placed in the magnetic meridian with its south pole pointing north. The null point is obtained 20 cm away from the centre of the magnet. If the earth’s magnetic field (horizontal component) at this point is 0.3 gauss, the magnetic moment of the magnet is

•   8.0×10² e.m.u
•  1.2×10³ e.m.u
•  2.4×10³ e.m.u
•  3.6×10³ e.m.u

Solution
                           

Q24. Hysteresis loss is minimized by using

•  Alloy of steel
•  Shell type of core
•  Thick wire which has low resistance
•  Mu metal

Solution
Hysteresis loss is minimised by using Mu metal.

Q25.A magnet of length 0.1 m and pole strength 10^-4 A-m is kept in a magnetic field of 30 Wb m^-2 at an angle 30°. The couple acting on it is ……..×10^-4 Nm.

•  3.0
•  4.5
•  1.5
•  1.5

Solution
                          

Q26. If the angular momentum of an electron is J ⃗ then the magnitude of the magnetic moment will be

•  eJ/m
•  eJ/2m
• eJ 2m
•  2m/eJ

Solution
                         

Q27.A deflection magnetometer is adjusted in the usual way. When a magnet is introduced, the deflection observed is θ, and the period of oscillation of the needle in the magnetometer is T. When the magnet is removed, the period of oscillation is T₀.Find the relation between T and T₀ is

•  T²=T₀² cos θ
•  T=T₀ cos θ
•  T=T₀/cosθ
•  T²=(T₀²)/cosθ

Solution
                             

Q28.A long magnetic needle of length 2L, magnetic moment M and pole strength m units is broken into two pieces at the middle. The magnetic moment and pole strength of each piece will be

•  M/2,m/2
•  M,m/2
•  M/2,m
•  M,m

Solution
                                   

Q29.A solenoid has core of a material with relative permeability 500 and its windings carry a current of 1A. The number of turns of the solenoid is 500 per metre. The magnetization of the material is nearly

•  2.5×10³ Am^-1
•  2.5×10⁵ Am¹
•  2.0×10³ Am^-1
•  2.0×10⁵ Am^-1

Solution
                                 

Q30. Two short magnets with their axes horizontal and perpendicular to the magnetic meridian are placed with their centres 40 cm east and 50 cm west of magnetic needle. If the needle remains undeflected, the ratio of their magnetic moments M₁:M₂ is

•  4∶5
•  16∶25
•  64∶125
• 2∶√5

Solution