मराठी
महाराष्ट्र राज्य शिक्षण मंडळएस.एस.सी (इंग्रजी माध्यम) इयत्ता १० वी

Electromagnetic induction means ______.

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प्रश्न

Electromagnetic induction means ______.

पर्याय

  • Charging of an electric conductor.

  • Production of magnetic field due to a current flowing through a coil.

  • Generation of a current in a coil due to relative motion between the coil and the magnet.

  • Motion of the coil around the axle in an electric motor.

MCQ
रिकाम्या जागा भरा
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उत्तर

Electromagnetic induction means generation of a current in a coil due to relative motion between the coil and the magnet.

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  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 4: Effects of electric current - Exercises [पृष्ठ ६०]

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बालभारती Science and Technology Part 1 [English] Standard 10 Maharashtra State Board
पाठ 4 Effects of electric current
Exercises | Q 3 | पृष्ठ ६०

संबंधित प्रश्‍न

The device used for producing electric current is called _________.


State three differences between direct current and alternating current.


Explain different ways to induce current in a coil.


 Two circular coils A and B are placed closed to each other. If the current in the coil A is changed, will some current be induced in the coil B? Give reason.


A rectangular wire loop of sides 8 cm and 2 cm with a small cut is moving out of a region of uniform magnetic field of magnitude 0.3 T directed normal to the loop. What is the emf developed across the cut if the velocity of the loop is 1 cm s−1 in a direction normal to the

  1. longer side,
  2. shorter side of the loop? 

For how long does the induced voltage last in each case?


What is electromagnetic induction?


Prove theoretically  (electromagnetic induction) `e = (dphi)/(dt)`


Name a common device that uses electromagnets.


 How does an electromagnet differ forma permanent magnet?  

 


 Explain why, the core of an electromagnet should be of soft iron and not of steel. 


 State the factors on which the strength of an electromagnet depends. How does it depend on these factors?


The direction of current in the coil at one end of an electromagnet is clockwise. This end of the electromagnet will be:

(a) north pole
(b) east pole
(c) south pole
(d) west pole


 Name one device which works on the phenomenon of electromagnetic induction. 


An induced current is produced when a magnet is moved into a coil. The magnitude of induced current does not depend on:  

(a) the speed with which the magnet is moved
(b) the number of turns of the coil
(c) the resistivity of the wire of the coil
(d) the strength of the magnet


In which of the following case does the electromagnetic induction occur?

A loop of wire is held near a magnet.


The coil of a moving-coil galvanometer keeps on oscillating for a long time if it is deflected and released. If the ends of the coil are connected together, the oscillation stops at once. Explain.


Draw and label the diagram of a simple D.C. motor.
(a) Explain the rotation of the coil, giving a reason for your answer.
(b) How can you reverse the direction of rotation of the armature?
(c) How can you increase the speed of rotation of the motor?


Why do you mean by turns ratio of a transformer? Can it work with D.C.?

Fill in the blanks by writing (i) Only soft iron, (ii) Only steel, (iii) Both soft-iron and steel for the material of core and/or magnet.

Transformer______.


Name the following diagram and explain the concept behind it.


What is an electromagnet?


Draw a labelled diagram to show how an electromagnet is made.


State the purpose of soft iron core used in making an electromagnet.


Why soft iron is preferred to be used as the core of the electromagnet of an electric bell?


What for an inductor is used? Give some examples.


A coil of 200 turns carries a current of 4 A. If the magnetic flux through the coil is 6 x 10-5 Wb, find the magnetic energy stored in the medium surrounding the coil.


A coil of 200 turns carries a current of 0.4 A. If the magnetic flux of 4 mWb is linked with each turn of the coil, find the inductance of the coil.


Using Lenz’s law, predict the direction of induced current in conducting rings 1 and 2 when the current in the wire is steadily decreasing.


What should be the core of an electromagnet?


Ansari Sir was demonstrating an experiment in his class with the setup as shown in the figure below.

A magnet is attached to a spring. The magnet can go in and out of the stationary coil. He lifted the Magnet and released it to make it oscillate through the coil.
Based on your understanding of the phenomenon, answer the following question.

What will be observed when the Magnet starts oscillating through the coil. Explain the reason behind this observation.


Name some equipment that uses electromagnetism for functioning.


Which of the following instruments works by electromagnetic induction?


For making a strong electromagnet the material of the core should be ______.


Which of the following phenomena makes use of electromagnetic induction?


A rectangular, a square, a circular and an elliptical loop, all in the (x - y) plane, are moving out of a uniform magnetic field with a constant velocity `vecv = vhati`. The magnetic field is directed along the negative z-axis direction. The induced emf, during the passage of these loops, out of the field region, will not remain constant for ______.


In the given circuit, initially switch S1 is closed and S2 and S3 are open. After charging of capacitor, at t = 0, S1 is open and S2 and S3 are closed. If the relation between inductance capacitance and resistance is L = 4CR2 then the time (in sec) after which current passing through capacitor and inductor will be same is ______ × 10-4 N. (Given R = ℓn(2), L = 2mH)


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