state the component in the transformer to which the a.c. generator is connected
Answers
Answer:
Check this answer
Explanation:
(a) Principle:
It works on the principle of Faraday’s law of electromagnetic induction. Whenever a coil is rotated in a uniform magnetic field about an axis perpendicular to the field, the magnetic flux linked with coil changes and an induced emf is set up across its ends.
Working:
When the coil starts rotating with the arm AB moving up and the arm CD moving down, cutting the magnetic lines of force, then according to Fleming's right-hand rule and the induced current is set up in these arms along the direction of AB and CD. So an effective induced current flowing in the direction of ABCD is obtained.
If there are large number of turns in the coil, the current generated in each turn adds upto give a large quantity of current through the coil.
After half rotation of the coil, its arm CD starts moving up and AB moving down. As a result, the direction of the induced currents gets reversed in the coil in the direction of DCBA. Thus after every half rotation the polarity of the current in the respective arm changes. Such a current, which changes its direction after equal intervals of time, is called to get a direct current a split ring type commutator must be used in place of slip ring commutator.
emf induced in a coil
Consider a coil of N turns and area A being rotated at a constant angular velocity ω in a magnetic field of flux density B, its axis being perpendicular to the field.
When the normal to the coil is at an angle θ to the field, the flux through the coil is BAN cosθ = BAN cos(ω)t, since θ = ωt.
E=− dt /dϕ
E=− dt /d(BANcosθ)
E=BANωsin(ωt)
The maximum value of the e.m.f (E o
) is when θ (= ωt) = 90o (that is, the coil is in the plane of the field as shown in Figure 2) and is given by
E
o
=BANω
B. We know that e = Blv
but tanθ=
B
H
B
v
B
v
=B
H
tanθ
e=B
v
lV
e=B
H
tanθlV
e=5×10
−4
(tan30
o
)(20)(500) Volt
so e = 2.88 volt
AC generator is connected to ”Electromagnetic Induction”.
Explanation:
- An AC generator consists of two poles is the north pole and south pole of a magnet so that we can have a uniform magnetic field. There is also a coil which is rectangular in shape that is the armature.
- These coils are connected to the slip rings and attached to them are carbon brushes.
- The slip rings are made of metal and are insulated from each other. The brushes are carbon brushes and one end of each brush connects to the ring and other connects to the circuit.
- The rectangular coils rotate about an axis which is perpendicular to the magnetic field. There is also a shaft which rotates rapidly.