Physics
(a) What name is given to a cylindrical coil of diameter less than it's length?
(b) If a piece of soft iron is placed inside the coil mentioned in part (a) and current is passed in the coil from a battery, what name is then given to the device so obtained?
(c) Give one use of the device mentioned in part (b).
Related Questions
Show with the aid of the diagram how a wire is wound on a U-shaped piece of soft iron in order to make it an electromagnet. Complete the circuit diagram and label the poles of the electromagnet.
The diagram in figure shows a spiral coil wound on a hollow cardboard tube AB. A magnetic compass is placed close to it. Current is switched on by closing the key.
(a) What will be the polarity at the ends A and B?
(b) How will the compass needle be affected? Give reason.
Figure shows the current flowing in the coil of wire wound around the soft iron horse shoe core.
(a) State the polarities developed at the ends A and B.
(b) How will the polarity at the ends A and B change on reversing the direction of current.
(c) Suggest one way to increase the strength of magnetic filed produced.
You are required to make an electromagnet from a soft iron bar by using a cell, an insulated coil of copper and a switch. (a) Draw a circuit diagram to represent the process. (b) Label the poles of the electromagnet.