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A coil has a self-inductance of 0·05 Henry. Find the magnitude of the emf induced in it when the current flowing through it is changing at the rate of 100 As-1.
Concept: Electromagnetic Induction
Find magnetic flux density at a point on the axis of a long solenoid having 5000 tums/m when it carrying a current of 2 A.
Concept: Magnetic Flux
A circular coil has radius ‘r', number of turns ‘N’ and carries a current ‘I’. Magnetic flux density ‘B’ at its centre is ______.
Concept: Magnetic Flux
When an electric current is passed through a wire or a coil, a magnetic field is produced. Is the reverse phenomenon possible i.e, can a magnetic field produce an electric current? Explain with the help of an appropriate example.
Concept: Electromagnetic Induction
The Figure below shows an infinitely long metallic wire YY' which is carrying a current I'.
P is a point at a perpendicular distance r from it.
- What is the direction of magnetic flux density B of the magnetic field at the point P?
- What is the magnitude of magnetic flux density B of the magnetic field at the point P?
- Another metallic wire MN having length l and carrying a current I is now kept at point P. If the two wires are in vacuum and parallel to each other, how much force acts on the wire MN due to the current I' flowing in the wire YY'?
Concept: Magnetic Flux
A transformer is used to step up an alternating emf of 200V to 440V. If the primary coil has 1000 turns, calculate the number of turns in the secondary coil.
Concept: Transformers
An a.c generator generates an emf 'ε' where ε = 314 Sin (50πt) volt. Calculate the frequency of emf ε.
Concept: Transformers
What is the turns ratio i.e., transformer ratio, ns: np, in an ideal transformer which in-creases ac voltage from 220 V to 33000 V?
Concept: Transformers
In an ideal transformer, an output of 66 kV is required when an input voltage of 220 V is available. If the primary has 300 turns, how many turns should the secondary have?
Concept: Transformers
What is the ideal transformer?
Concept: Transformers
The primary coil of a transformer has 60 turns whereas its secondary coil has 3000 turns.
If a 220 V ac voltage is applied to the primary coil, how much emf is induced in the secondary coil?
Concept: Transformers
The primary coil of a transformer has 60 turns whereas its secondary coil has 3000 turns.
If a current of 5A flows in the primary coil, how much current will flow in a load in the secondary coil? State the assumption you have made regarding the transformer, in this calculation.
Concept: Transformers
What type of transformer is used in a mobile phone charger?
Concept: Transformers
Explain why core of a transformer is always laminated.
Concept: Transformers
State Moseley's law
Concept: Electromagnetic Spectrum
To which regions of the electromagnetic spectrum do the following wavelengths belong:
(a) 250 nm
(b) 1500 nm
Concept: Electromagnetic Spectrum
Arrange the following electromagnetic waves in increasing order of their frequencies (i.e. begin with the lowest frequency):
Visible light, y rays, X rays, microwaves, radio waves, infrared radiations, and ultraviolet radiation.
Concept: Electromagnetic Spectrum
Name the part of the electromagnetic spectrum which is:
Suitable for radar systems used in aircraft navigation.
Concept: Electromagnetic Spectrum
Name the part of the electromagnetic spectrum which is:
Produced by bombarding a metal target with high electrons.
Concept: Electromagnetic Spectrum
Calculate the shortest wavelength of electromagnetic radiation present in Balmer series of hydrogen spectrum.
Concept: Electromagnetic Spectrum
