Electro- magnetism questions | form six Physics

Define the following terms.

1. Ampere
2. Hysteresis.

Two parallel conductors A and B are situated 0.16m apart . Conductor A, caries a current of 4A and conductor B, carries a current of 8A. The directions of the currents are shown in Figure 1. Find the distance from A to a point where the magnetic fields due to A and B cancel each other (Ignore the effects of the earth`s magnetic field).

State the law of force acting on a conductor of length/ carrying an electric current in a magnetic field.

1. Draw the diagram of the solenoid with certain number of turns placed in the magnetic field and indicate any suitable directions of the flow of current in it.
2. Write down the formulae for the magnetic field induced at the centre of solenoid.

It is desired to design a solenoid that produces a magnetic field of O.I.T at the centre. If the radius of solenoid is 5cm, its length is 50cm and carries a current of 10A; Calculate:

1. The number of turns per unit length of the solenoid.
2. The total length of a wire required.

State the Biot-Savart law.

In a hydrogen atom, an electron keeps moving around its nucleus with a constant speed of 2.18x10⁶ms^-1. Assuming  that the orbit is a circular of radius 5.3x10^-11m, determine the magnetic flux density produced at the site of the proton in the nucleus.

State any three magnetic components of the earth`s magnetic field.

The horizontal and vertical components of the earth`s magnetic field at a certain location are 2.7x10<sup>-5</sup>T and 2.0x10<sup>-5</sup>T respectively. Determine the earth`s magnetic field at the location and its angle of inclination I.

State the following laws or theorems as applied in magnetism.

1. Biot-Savart law
2. Ampere`s theorem