1. Current is passed from South to North through a conductor placed below a freely pivoted magnetie 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 deflection of the
magnetic needle? Explain
Answers
Answer:
a) The north pole of the compass needle deflects towards the east.
b) Right-hand thumb rule.
c) Imagine that you are holding a current-carrying straight conductor in your right hand such that the thumb points towards the direction of current. Then your fingers will wrap around the conductor in the direction of the field lines of the magnetic field.
Explanation:
a) If we Place a straight current carrying wire (the direction of the flow of current is from south to north) such that the wire is placed below a compass needle and the wire is parallel to the compass needle, then the north pole of the compass needle deflects towards the east.
b) Rule used to arrive the inference :
A convenient way of finding the direction of magnetic field associated with a current-carrying conductor is using right-hand thumb rule.
c) This rule is explained as follows
Imagine that you are holding a current-carrying straight conductor in your right hand such that the thumb points towards the direction of current. Then your fingers will wrap around the conductor in the direction of the field lines of the magnetic field, as shown in Figure.
As per this rule , above the wire, magnetic field lines are emerging out of plane of figure. Hence magnetic field direction is from west to east.
Once we know the magnetic field direction surrounding the wire, we can determine the deflection direction of compass needle because
we know that north pole of magnetic needle of compass will align in the direction of magnetic field
