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प्रश्न
What do you understand by the term "electromagnetic induction"? Explain with the help of a diagram.
उत्तर
In case of relative motion between a source of magnetic field and conductor, current flows inside the conductor. This phenomenon is called electromagnetic induction. For example, when a bar magnet is moved towards a coil of wire attached to a galvanometer, a deflection in galvanometer needle is observed due to induced current as shown in the figure.
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संबंधित प्रश्न
State three ways in which the strength of an electromagnet can be increased.
State whether the following statement are true or false:
A generator works on the principle of electromagnetic induction.
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.
List two ways of increasing the strength of an electromagnet if the material of the electromagnet is fixed.
Using Ampere's law, obtain an expression for the magnetic induction near a current-carrying straight infinitely long wire.
The magnetic flux passing through a coil perpendicular to its plane is a function of time and is given by OB = (2t3 + 4t2 + 8t + 8) Wb. If the resistance of the coil is 5 Ω, determine the induced current through the coil at a time t = 3 second.
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.
Which of the following instruments works by electromagnetic induction?
AB is a coil of copper wire having a large number of turns. The ends of the coil are connected with a galvanometer as shown. When the north pole of a strong bar magnet is moved towards end B of the coil, a deflection is observed in the galvanometer.
- State the reason for using galvanometer in the activity and why does its needle deflects momentarily when magnet is moved towards the coil.
- What would be observed in the galvanometer in a situation when the coil and the bar magnet both move with the same speed in the same direction? Justify your answer.
- State the conclusion that can be drawn from this activity.
Will there be any change in the momentary deflection in the galvanometer if number of turns in the coil is increased and a more stronger magnet is moved towards the coil?
OR
What is electromagnetic induction? What is observed in the galvanometer when a strong bar magnet is held stationary near one end of a coil of large number of turns? Justify your answer.
In the current carrying conductor (AOCDEFG) as shown, the magnetic induction at point O is ______.
(R1 and R2 are radii of CD and EF respectively. l = current in the loop, μ0 = permeability of free space)
