Advertisements
Advertisements
Question
On which type of current do transformers work?
Advertisements
Solution 1
The transformer works on alternating current or A.C. current.
Solution 2
No, they aren't suitable for use with direct current because, in the absence of a change in the magnetic field lines connected to the coils, no induced current can flow in the other coil.
APPEARS IN
RELATED QUESTIONS
Derive an expression for ratio of e.m.f.s and currents in terms of number of turns in primary and secondary coil.
A transformer converts 240 V AC to 60 V AC. The secondary has 75 turns. The number of turns in primary are _______.
(A) 600
(B) 500
(C) 400
(D) 300
Complete the following sentence :
……… energy is converted into …………energy by an electric motor.
Describe, with the help of a suitable diagram, the working principle of a step-up transformer. Obtain the relation between input and output voltages in terms of the number of turns of primary and secondary windings and the currents in the input and output circuits.
State the factors on which the frequency of the alternating e.m.f. depends.
(i) Draw a clear labelled diagram of an electric bell.
(ii) Explain in brief, its working.
(iii) What material is used for the core of an electric bell? State the reason.
Explain step up and step down transformer?
Name one electrical device which works on Faraday's law of electromagnetic induction principle.
Magnetic flux passing through a coil is initially 4 × 10-4 Wb. It reduces to 10% of its original value in t second. If the emf induced is 0. 72 mV then t in second is ______.
In an ideal transformer, the turns ratio is `N_p/N_s = 1/2`. The ratio Vs : Vp is equal to (the symbols carry their usual meaning):
