ICSE 2009 Solved Important Papers of Physics By Mr. M.P.Keshari

ICSE Guess > ICSE Papers > Important Questions > Class X > 2009 > Physics > Physics By Mr. M.P.Keshari

Electromagnetism (Solved)

Question .1. Describe the construction and working of a simple step-up transformer.

Or,  

What is the function of a step-up transformer?

Answer : Click Here

Question .2. Name the principle on which the functioning of a transformer depends?

Answer : Click Here

Question .3. Can a transformer work when it is connected to a dc source?

Answer : Click Here

Question .4. (i) Draw a neat labelled diagram of an ac generator.

(ii) What is the magnitude of emf induced in the coil when its plane becomes parallel to the magnetic field.

(iii) State two ways by which the emf in an ac generator can be increased.

Answer : Click Here

Question .5. State two ways of increasing the speed of a dc motor.

Answer : Click Here

Question .6. State the energy transformations taking place in the following

(i) electric cell and

(ii) electric generator.

Answer : Click Here

Question .7. (i) Draw a labelled diagram of the device you would use to transform 200 V ac to 15 V ac.

(ii) What is the name of this device?

Or,

Draw a labelled diagram to show the various components of a step down transformer .

Answer : Click Here

Question .8. What is an electromagnet? State two ways in which, the strength of an electromagnet can be increased.

Answer : Click Here

Question .9. State two characteristics of a primary coil of a step-up transformer when compared to the secondary coil.

Answer : Click Here

Question .10. With reference to the dc motor state

(i) the energy change that takes place and

(ii) the principle on which it operates.

Answer : Click Here

Question .11. (a) Draw a representative diagram of a dc motor . Label the following in your diagram

(i) the field magnet

(ii) the armature

(iii) commutator and

(iv) brushes. What is the energy changes involved in this case?

(b) State the function of the split ring.

Answer : Click Here

Question .12. Draw a sketch of an electric bell with electrical connections and label the main parts. Why the armature is made of soft iron and not steel?

Answer : Click Here

Question .13. State the main difference between a step-up and step-down transformer.

Answer : Click Here

Question .14. Explain briefly how a magnet can be demagnetized using an alternating current.

Answer : Click Here

Question .15. State the energy change which takes place when a magnet is moved inside a coil having a galvanometer at its ends. Name this phenomenon.

Answer : Click Here

Question .16. Mention two reasons why a soft iron core is used within the coil of a moving coil galvanometer.

Answer : Click Here

Question .17. State two advantages of an electromagnet over a permanent magnet.

Answer : Click Here

Question .18. (i) What will happen to a compass needle when the compass is placed below a wire and a current is made to flow the wire? Give a reason to justify your answer.

(ii) What energy conversion takes place during the working of a d.c. motor?

Answer : Click Here

Q.19. (i) State two factors on which the strength of an induced current depends.

(ii) When a solenoid that is carrying current is freely suspended, it comes to rest along a particular direction. Why does this happen?

(iii) What will be the effect on the working of an electric bell if instead of a direct current, an alternating current is used?

Answer : Click Here

Paper By Mr. M. P. Keshari [ For Further Enquiry 09434150289]