The direction of a magnetic field due to a straight current carrying conductor can be determined using:

Correct option is B

· The Right Hand Thumb Rule is used to determine the direction of the magnetic field around a straight current-carrying conductor.
· According to this rule, if you hold the conductor in your right hand with the thumb pointing in the direction of the current, the curled fingers around the conductor indicate the direction of the magnetic field.
Key Points:
· Right Hand Thumb Rule: Determines the circular direction of the magnetic field around the conductor.
· Magnetic Field Lines: Form concentric circles around the conductor, with their direction determined by the current's flow.
· Practical Application: This rule is vital in understanding electromagnetism and designing devices like solenoids and motors.
Additional Information:
· Fleming’s left-hand rule: Used to determine the direction of force acting on a current-carrying conductor in a magnetic field.
· Left hand thumb rule: Not a standard rule for determining magnetic field direction.
· Fleming’s right-hand rule: Used to find the direction of induced current in electromagnetic induction.