Advertisements
Advertisements
प्रश्न
State two factors on which the magnitude of an induced e.m.f. in the secondary coils of a transformer depends.
Advertisements
उत्तर
The magnitude of an induced e.m.f. in the secondary coil of a transformer depends on the following two factors:
- The ratio of the number of turns in the secondary coil to the number of turns in the primary coil.
- The magnitude of e.m.f. applied in the primary coil.
APPEARS IN
संबंधित प्रश्न
The diagram shows a coil wound around a U-shaped soft iron bar AB.
- What is the polarity induced at the ends A and B when the switch is pressed?
- Suggest one way to strengthen the magnetic field in the electromagnet.
- What will be the polarities at A and B if the direction of current is reversed in the circuit?
You are given an iron nail, a torch cell, and a long piece of insulated copper wire. With the help of a labelled neat diagram, describe in steps how you will make the nail, an electromagnet.
Show with the aid of a diagram how a wire is wound on a U-shaped piece of soft iron in order to make it an electromagnet. Complete the circuit diagram and label the poles of the electromagnet.
Name the type of transformer shown in Fig. What changes will you observe regarding the brightness of the lamp, if
- the number of turns in the secondary is doubled? Explain.
- the part X of the transformer is removed?
- the core of the transformer is made out of copper?
- the A.C. supply is replaced by D.C.?
Fill in the blanks by writing (i) Only soft iron, (ii) Only steel, (iii) Both soft-iron and steel for the material of core and/or magnet.
Electric bell ______.
What will be the effect on the working of an electric bell if instead of a direct current an alternating current is used?
State the principle of a D. C. motor.
What is dynomo (a.c. generator)? State the principle on which it works.
The primary windings of a step-up transformer are usually made of thicker wire than the secondary. Explain.
Which magnet will you use?
Iron is to be separated from trash.
