Quiz về Điện Từ

The magnetic field is not generated by

• stationary charge.

• moving charge.

• steady current.

• alternating current.

Choose the incorrect statement. The magnetic force is the interaction force between

• magnet and current

• current and current

• magnet and stationary charge

• magnet and magnet

The unit of magnetic flux density is

• Volt (V).

• Tesla (T).

• Henry (H).

• Weber (Wb).

A wire segment of length 1, with a current of 1 flowing through it and placed horizontally in a magnetic field with vertical field lines from top to bottom, experiences a magnetic force F. The magnetic flux is determined by the expression:

A current-carrying wire with a current of 2A is perpendicular to the field lines of a uniform magnetic field. The magnetic flux density has a magnitude of 0.02T. The magnetic force acting on 20cm of the wire has a magnitude of

• 6N

• 8N

• 8mN

• 6mN

The unit of magnetic flux is:

• Weber (Wb)

• Tesla (T)

• Coulomb (C)

• Henry (H)

For a coil with N turns, area S placed in a uniform magnetic field with magnetic flux density B. The magnetic flux vector makes an angle a with the normal vector of the coil. The formula for calculating the magnetic flux through the coil is

• Ф = BS.

• Ф = NBS cos a.

• varphi = BS sin a.

• Ф = I(R + r)

The formula for calculating the effective current intensity based on the maximum current intensity is

The maximum voltage of household alternating current in Vietnam is

• 220 V.

• 110 V.

• 110√2 V.

• 220√2 V.

The electromotive force in a closed circuit has the expression