Advertisements
Advertisements
Question
Which of the following scientist invented the rule of electromagnetic induction?
Options
Newton
Kepler
Mendeleev
Michael Faraday
Advertisements
Solution
Michael Faraday
RELATED QUESTIONS
Explain different ways to induce current in a coil.
A line charge λ per unit length is lodged uniformly onto the rim of a wheel of mass M and radius R. The wheel has light non-conducting spokes and is free to rotate without friction about its axis (Figure). A uniform magnetic field extends over a circular region within the rim. It is given by,
B = − B0 k (r ≤ a; a < R)
= 0 (otherwise)
What is the angular velocity of the wheel after the field is suddenly switched off?

An emf of 2V is induced in a coil when the current in it is changed from 0A to 10A in 0·40 sec. Find the coefficient of self-inductance of the coil.
When an electric current is passed through any wire, a magnetic field is produced around it. Then why an electric iron connecting cable does not attract nearby iron objects when electric current switched on through it?
What is an electromagnet? Describe the construction and working of an electromagnet with the help of a labelled diagram.
Explain why, the core of an electromagnet should be of soft iron and not of steel.
The north-south polarities of an electromagnet can be found easily by using:
(a) Fleming's right-hand rule
(b) Fleming's left-hand rule
(c) Clock face rule
(d) Left-hand thumb rule
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
What condition is necessary for the production of current by electromagnetic induction?
State whether the following statement are true or false:
A motor works on the principle electric generator?
What do you understand by the term "electromagnetic induction"? Explain with the help of a diagram.
Name and state the law which determines the direction of induced current.
or
State Fleming’s right-hand rule.
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.
Draw a simple labeled diagram of a step-up transformer.
The following diagram shows a fixed coil of several turns connected to a center zero galvanometer G and a magnet NS which can move in the direction shown in the diagram.
- Describe the observation in the galvanometer if
- The magnet is moved rapidly,
- The magnet is kept still after it has moved into the coil
- The magnet is then rapidly pulled out the coil.
- How would the observation in (i) of part (a) change if a more powerful magnet is used?

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?
Name the following diagram and explain the concept behind it.

State the purpose of soft iron core used in making an electromagnet.
Draw a labelled diagram to make an electromagnet from a soft iron bar. Mark the polarity at its ends in your diagram. What precaution would you observe while making it?
Using Ampere's law, obtain an expression for the magnetic induction near a current-carrying straight infinitely long wire.
Observe the given figure of Fleming’s Right Hand Rule and write the labels of A and B correctly.

What for an inductor is used? Give some examples.
Establish the fact that the relative motion between the coil and the magnet induces an emf in the coil of a closed circuit.
Obtain an expression for motional emf from Lorentz force.
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.
We can induce the current in a coil by ____________.
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 ______.
Induced current flows through a coil ______.
For making a strong electromagnet the material of the core should be ______.
Sea turtles return to their birth beach many decades after they were born due to ______.
A galvanometer is an instrument that can detect the presence of a current in a circuit.
Which of the following phenomena makes use of electromagnetic induction?
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)

One solenoid is centered inside another. The outer one has a length of 50.0 cm and contains 6750 coils, while the coaxial inner solenoid is 3.0 cm long and π cm2 in area and contains 150 coils. The current in the outer solenoid is changing at 3000 A/s. The emf induced in the inner solenoid is ______ V.
(Round off to two decimal places.)
The charge will flow through a galvanometer of resistance 200Ω connected to a 400Ω circular coil of 1000 turns wound on a wooden stick 20 mm in diameter, if a magnetic field B = 0.012 T parallel to the axis of the stick decreased suddenly to zero, is near ______.
