Physics
On reversing the direction of current in a wire, the magnetic field produced by it:
- gets reversed in direction
- increases in strength
- decreases in strength
- remains unchanged in strength and direction.
Related Questions
Which of the following statements is not true for an electromagnet ?
- It is made of soft iron.
- Its magnetic field strength can be changed.
- The polarity of an electromagnet cannot be changed.
- It can easily be demagnetised.
The magnetic field lines inside a solenoid are :
- parallel and circular
- straight and parallel to the axis of solenoid
- straight and perpendicular to the axis of solenoid
- circular
Horse shoe magnets are used in :
- d.c. motor
- a.c. generator
- electric bell
- all of the above
Two infinitely long parallel wires carry equal currents in the same direction. The magnetic field at the mid-point in between the two wires is :
- Twice the magnetic field produced due to each of the wire.
- Half of the magnetic field produced due to each of the wire.
- Zero
- Square of the magnetic field produced by each wire.