Advertisements
Advertisements
Question
Why is the iron core of a transformer made laminated (thin sheets) instead of being in one solid piece?
Advertisements
Solution
Laminated thin sheets assist limit energy loss by producing strong field lines and eddy currents in the core. It lessens core hysteresis loss as well.
APPEARS IN
RELATED QUESTIONS
Derive an expression for e.m.f. and current in terms of turns ratio
Express the turn ratio in terms of voltages.
The teachers of Geeta’s school took the students on a study trip to a power generating station, located nearly 200 km away from the city. The teacher explained that electrical energy is transmitted over such a long distance to their city, in the form of alternating current (ac) raised to a high voltage. At the receiving end in the city, the voltage is reduced to operate the devices. As a result, the power loss is reduced. Geeta listened to the teacher and asked questions about how the ac is converted to a higher or lower voltage.
1) Name the device used to change the alternating voltage to a higher or lower value. State one cause for power dissipation in this device.
2) Explain with an example, how power loss is reduced if the energy is transmitted over long distances as an alternating current rather than a direct current.
3) Write two values each shown by the teachers and Geeta.
How is the e.m.f. across primary and secondary coils of a transformer related with the number of turns of the coil in them?
The transformer is used in ______ current circuits.
The primary coil of a transformed has 800 urns and the secondary coil has 8 turns. It is connected to a 220 V a.c. supply. What will be the output voltage?
A transformer is designed to work from a 240 V a.c. mains and to give a supply of 8 V to ring a house bell. The primary coil has 4800 turns. How many turns will be in the secondary coil?
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.
Define a Transformer.
How do the input and output powers in a transformer compare? State the assumption made.
