How does the magnetic field produced by a current-carrying straight wire vary with the distance from the wire?

How is the relative strength of a magnetic field shown around a magnet?

Why does a current-carrying conductor experience a force when it is placed in a magnetic field? State Fleming's left-hand rule.

From which of the following cases,will the induced current in the loop not be obtained?

Name four appliances wherein an electric motor,a rotating device that converts electrical energy to mechanical energy,is used as an important component. In what respect are motors different from generators?

$(a)$ What is meant by a 'magnetic field'?
$(b)$ How is the direction of magnetic field at a point determined?
$(c)$ Describe an activity to demonstrate the direction of the magnetic field generated around a current-carrying conductor.
$(d)$ What is the direction of the magnetic field at the centre of a current-carrying circular loop?