Q2 of 7 Page 147

How will you determine the polarity when current is passed through a solenoid? Suggest methods for increasing the strength of the magnetic field around a current carrying solenoid.

The polarity when current is passed through a solenoid can be determined by clock rule.

According to the clock rule, if we find that in a coil the current is flowing in anti-clock wise direction then the face of the coil will behave like the north pole while; if the current is flowing in clock wise direction then the face of the coil will behave like the south pole.


The strength of the field can be increased by:


a) Increasing the number of turns per meter of the solenoid


b) Increasing the current through it.


More from this chapter

All 7 →
1

Current is passed from south to north through a conductor placed below a freely pivoted magnetic needle.

a) To which direction will the north pole of the magnetic needle turn?


b) Which is the rule used to arrive at this inference?


c) State the rule.


d) If the current flows in the conductor in the east west direction, what do you guess about the magnetic needle? Explain.

 3

State the Motor Rule. If the directions of current in the conductor and the magnetic field are the same, in which way will the conductor move?

 1

Construct a simple DC motor and show its working.

 2

Draw the lines of force around a solenoid and exhibit it.