Electromagnetic-Induction-Quiz-8

Electromagnetic Induction Quiz-8

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. 

Q71. The graph shows the variation in magnetic flux ϕ(t) with time through a coil. Which of the statements given below is not correct

                                  

•  There is a change in the direction as well as magnitude of the induced emf between B and D
•  The magnitude of the induced emf is maximum between B and C
•  There is a change in the direction as well as magnitude of induced emf between A to C
•  The induced emf is not zero at B

Solution
                     

Q72.Coefficient of coupling between two coils of self-inductances L₁ and L₂ is unity. It means

•  50% flux of L₁ is linked with L₂
•  100% flux of L₁ is linked with L₂
•  √(L₁ ) time of flux of L₁ is linked with L₂
•  None of the above

Solution
                       

Q73.  A small piece of metal wire is dragged across the gap between the pole pieces of a magnet in 0.5 second. The magnetic flux between the pole pieces is known to be 8×10^-4 Wb. The emf induced in the wire is

•   16 mV
•  1.6 V
•  1.6 mV
•  16 V

Solution
                         

Q74. The current in a coil changes from 4 ampere to zero in 0.1 s. If the average e.m.f. induced is 100 volt, what is the self inductance of the coil

•  2.5 H
•  25 H
•  400 H
•  40 H

Solution
                         

Q75.The magnetic flux linked with the coil varies with time as ϕ=3t²+4t+9. the magnitude of the induced emf at 2 s is

•  9 V
•  16 V
•  3 V
•  4 V

Solution
                            

Q76. A power transformer is used to step up an alternating e.m.f. of 220 V to 11 kV to transmit 4.4 kW of power. If the primary coil has 1000 turns, what is the current rating of the secondary? Assume 100% efficiency for the transformer

•  4 A
• 0.4 A
•  0.04 A
•  0.2 A

Solution
                       

Q77.A rectangular loop of sides 10 cm and 5 cm with a cut is stationary between the pole pieces of an electromagnet. The magnetic field of the magnet is normal to the loop. The current feeding the electromagnet is reduced so that the field decreased from its initial value of 0.3 T at the rate of 0.02 Ω. If the cut is joined and the loop has a resistance of 2.0 Ω, the power dissipated by the loop as heat is

•  5 nW
•  4 nW
•  3 nW
•  2 nW

Solution
                    

Q78.Two coils are placed close to each other. The mutual inductance of the pair of coils depends upon

•  The rates at which currents are changing in the two coils
•  Relative position and orientation of the two coils
•  The materials of the wires of the coils
•  The currents in the two coils

Solution
Mutual inductance of the pair of coils depends on distance between two coils and geometry of two coils.

Q79.A coil of N =100 turns carries a current I =5 A and creates a magnetic flux ϕ=10^-5 Tm² per turn. The value of its inductance L will be

•  0.05 mH
•  0.10 mH
•  0.15 mH
•  0.20 mH

Solution
                         

Q80. A transformer works on the principle of

•  Magnetic effect of the electrical current
•  Mutual induction
•  Electrical inertia
• Self induction

Solution
Mutual induction