Question

How is the working of an electric bell affected, if alternating current be used instead of direct current ?

Answer 1

The working of an electrical bell depends on the 'make and break' of the circuit. Is working is not affected by the type of current used. That is, alternating or direct current.
Both the currents activate the electromagnet and hence soft iron is pulled. In case of alternating current, the polarity of the electromagnet rapidly changes but it has no effect on the attractive power of the electromagnet.