Electric Bell

Which branch of physics deals with the study of the interaction that occurs between charged particles.

• Electromagnetic Induction

• Electromangetism

• Electricity

• Electromagnetism

Who invented the electric bell and in what year?

• Henry Asquith in 1841

• Michael Faraday in 1842

• Joseph Henry in 1831

• Charles Coulomb in 1803

An electric bell may be used in......

• Cell phones

• Alarms

• Telephones

• Doorknobs

All of the following are components of the electric bell except

• hammer

• gong

• amateur

• contact screw

Fill in the blank:

Current flows through the coils of wire creating a magnetic field. The soft iron core of the electromagnet becomes _____________ and attracts the soft iron armature. When the soft iron armature is pulled inwards the hammer strikes the bell.

• Demagnetized

• Magnetized

• Induced

• Electically active

Fill in the blanks:

When the circuit is broken, the __________ moves away from the contact screw. The current stops flowing and the electromagnet becomes _________. The springy metal strip pulls the armature back into its original position which allows it to make contact again with the circuit.

• armature, magnetized

• hammer, magnetized

• hammer, demagnetized

• armature, demagnetized

All of the following are advantages of the electric bell except

• Electric bells are cheap

• They operate on a medium voltage (15V - 30V)

• They can detect human/machine errors

• They are lightweight and portable

Select all that are disadvantages of the electric bell

• It requires a battery which may die sometimes unexpectedly.

• Spring may deteriorate overtime.

• It uses a lot of electricity

• It performs multiple times for a single push of the bell

True/False

An electric bell uses an electromagnet which is a permanent magnet.

• True

• False

What does the letter E represent in diagram above?

• Armature

• Soft core

• Contact spring

• Switch