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

Electromagnetic induction means ______.

Advertisements
Advertisements

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
Advertisements

उत्तर

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

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

APPEARS IN

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

संबंधित प्रश्‍न

The magnetic flux through a loop varies according to the relation Φ = 8t2 + 6t + C, where ‘C’ is constant, 'Φ' is in milliweber and 't' is in second. What is the magnitude of induced e.m.f. in the loop at t = 2 seconds.


A metal rod `1/sqrtpi `m long rotates about one of its ends perpendicular to a plane whose magnetic induction is 4 x 10-3 T. Calculate the number of revolutions made by the rod per second if the e.m.f. induced between the ends of the rod is 16 mV.


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?


 How does an electromagnet differ forma permanent magnet?  

 


Write some of the important uses of electromagnets.


The most suitable material for making the core of an electromagnet is:

(a) soft iron
(b) brass
(c) aluminium
(d) steel


When current is 'switched on' and 'switched off' in a coil, a current is induced in another coil kept near it. What is this phenomenon known as?


 What do you understand by the term "electromagnetic induction"? Explain with the help of a diagram. 


How is the working of an electric bell affected, if alternating current be used instead of direct current?


In which of the following case does the electromagnetic induction occur?
The current is stopped in a wire held near a loop of wire .


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

A magnet is moved through a loop of wire .


Welders wear special glass goggles while working. Why? Explain.


Welders wear special goggles or face masks with glass windows to protect their eyes from electromagnetic radiations. Name the radiations and write the range of their frequency.


Show diagrammatically how an alternating emf is generated by a loop of wire rotating in a magnetic field. Write the expression for the instantaneous value of the emf induced in the rotating loop.


A conducting square loop of side l and resistance R moves in its plane with a uniform velocity v perpendicular to one of its sides. A uniform and constant magnetic field Bexists along the perpendicular to the plane of the loop as shown in figure. The current induced in the loop is _____________ .


The switches in figure (a) and (b) are closed at t = 0 and reopened after a long time at t = t0.

(a) The charge on C just after t = 0 is εC.
(b) The charge on C long after t = 0 is εC.
(c) The current in L just before t = t0 is ε/R.
(d) The current in L long after t = t0 is ε/R.


Calculate the dimensions of (a) \[\int \overrightarrow{E} . d \overrightarrow{l,}\] (b) vBl and (c) \[\frac{d \Phi_B}{dt}.\] The symbols have their usual meaning.


Figure shows a wire sliding on two parallel, conducting rails placed at a separation l. A magnetic field B exists in a direction perpendicular to the plane of the rails. What force is necessary to keep the wire moving at a constant velocity v?


A transformer has 400 turns in the primary winding and 10 turns in the secondary winding. The primary e.m.f. is 250 V and the primary current is 2.0 A. calculate:
(a) The secondary voltage,
(b) The secondary current, assuming 100% efficiency.


State Fleming’s Right Hand Rule.


List some of the practical applications of an electromagnet.


The diagram shows a rectangular coil ABCD, suspended freely between the concave pole pieces of a permanent horseshoe magnet, such that the plane of the coil is parallel to the magnetic field.

  1. State your observation when the current is switched on.
  2. Give an explanation for your observation in (i).
  3. State the rule, which will help you to find the motion of rotation of the coil.
  4. In which position will the coil ultimately come to rest?
  5. State four ways of increasing the magnitude of force acting on the coil.

Which of the following scientist invented the rule of electromagnetic induction?


A square coil of side 30 cm with 500 turns is kept in a uniform magnetic field of 0.4 T. The plane of the coil is inclined at an angle of 30° to the field. Calculate the magnetic flux through 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.


A generator has an e.m.f. of 440 Volt and internal resistance of 4000 hm. Its terminals are connected to a load of 4000 ohm. The voltage across the load is ______.


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.

Consider the situation where the Magnet goes in and out of the coil. State two changes which could be made to increase the deflection in the galvanometer.


If the sun radiates energy at the rate of 3.6 × 1033 ergs/sec the rate at which the sun is loosing mass is given by ______.


Name some equipment that uses electromagnetism for functioning.


Which of the following instruments works by electromagnetic induction?


A conductor of length 50 cm carrying a current of 5 A is placed perpendicular to a magnetic field of induction 2×10 -3T. Find the force on the conductor.


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)mΩ, L = 2mH)


A sheet is placed on horizontal surface in front of a strong magnetic pole. A force is needed to:

  1. hold the sheet there if it is magnetic.
  2. hold the sheet there if it is non-magnetic.
  3. move the sheet away from the pole with uniform velocity if it is conducting.
  4. move the sheet away from the pole with uniform velocity if it is both, non-conducting and nonpolar.

Choose the correct statement(s) from the options given below:


Which movement of a coil can produce a current?


What did Faraday show in 1831?


Which device used for producing electricity works on electromagnetic induction?


Which charging technology works on electromagnetic induction?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×