Question

Which rule determines the direction of force experienced by a current carrying straight conductor placed in a magnetic field which is perpendicular to it?
$\left( a \right)$ Maxwell right hand grip rule
$\left( b \right)$ Fleming’s left hand rule
\[\left( c \right)\] Fleming’s right hand rule
$\left( d \right)$ None of the above

Answer 1

Hint: In this question think of the rule in which the middle finger points in the direction of current, thumb is for the direction of force and the index finger is in the direction of magnetic field. The rule that follows these protocols will give the right answer to this problem statement.

Complete step-by-step answer:
Fleming’s left hand rule –
Whenever a current carrying conductor is placed in a magnetic field, it experiences a force due to the magnetic field. The direction of force acting on the conductor can be found using Fleming's Left Hand Rule. The middle finger points in the direction of the current, thumb points in the direction of force and index finger points in the direction of magnetic field as shown in the figure.

All the lines are at right angles (i.e. at ${90^o}$) to each other as shown in the figure.
So we find out the direction of force due to magnetic induction.
So when the direction of the current is in the positive direction of the x-axis so according to Fleming’s right hand rule the direction of the magnetic field is in the positive direction of y-axis.
And if the direction of the current is in the positive direction of the y-axis so according to Fleming’s right hand rule the direction of the magnetic field is in the positive direction of x-axis.
And if the direction of the current is in the positive direction of the z-axis so according to Fleming’s right hand rule the direction of the magnetic field is in the positive direction of the y-axis.
So this is the required answer.
Hence option (B) is the right answer.

Note:There is a great bit of confusion regarding Fleming's left-hand rule and Fleming’s right hand rule, right hand rule is used to show the direction of induced current when a conductor is placed in a magnetic field. Moreover it can also be used to determine the direction of current in generator winding.