Physics Basic Unit#8 Test

In a loop of wire current is flowing clockwise the direction of magnetic field through loop is

• Outward

• Anticlockwise

• Inward

• None of these

A wire of length 2m carries a current of 10 A. What is the force acting on it when it is placed at an angle of 45° to the uniform magnetic field of 0.15 T?

• 1.2 N

• 3.2 N

• 2.5 N

• 3/√2 N

An electron of mass m is accelerated through a potential difference of V and then it enters a magnetic field of induction B normal to the lines. Then the radius of the circular path is

A wire carrying current I and other 2I in the same direction produces a magnetic field B at the mid-point. What will be the field when 2I wire is switched off at that point?

• B/2

• B/2

• B

• 4B

The magnetic lines of force inside a bar magnet

• Are from north pole to south pole of the magnet

• Does not exist

• Depend upon the area of cross-pole of the magnet

• Are from south pole to north pole of the magnet

In step up transformer, voltage in the secondary increases and power in secondary.

• Remain Same

• Decreases because voltage increases

• Increases because current decreases

• May increases if voltage remain same

In a region, steady and uniform electric and magnetic fields are present. These two fields are parallel to each other. A charged particle is released from rest in this region. The path of the particle will be

• Helix

• Straight line

• Ellipse

• Circle

Magnetism is related to ____:

• Stationary charge

• Moving charge

• Both A and B

• None of these

The Unit of the magnetic flux density is equal to:

• Weber

• Tesla

• N/C

• Wb/A

Which of the following does not affect the motion of a moving electron?

• Electric field applied in the direction of motion

• Magnetic field applied in the direction of motion

• Electric field applied perpendicular to the direction of motion

• Magnetic field applied perpendicular to the direction of motion