U1 L4 Questions

When the compass is put beside a wire carrying an Electric current .............

• no deflection occurs
• the compass needle deflects
• the compass needle will be destroyed
• no correct answer

The magnet which is made by the effect of electricity is called ............

• A. natural magnet
• B. magnetic substance
• C. electromagnet
• D. (b) and (c)

Magnetic effect of the electric current can be detected by using.............

• A. ammeter
• B. compass
• C. battery
• D. both (b) and (c)

The idea of operating the electromagnet is the changing of ......................

• kinetic energy into electric energy
• electric energy into mechanical energy
• magnetic energy into mechanical energy
• electric energy into magnetic energy

The bar used in the electromagnet is made up of ................

• aluminium
• wrought iron
• steel
• copper

The electromagnet is composed of ...........

• A. a copper wire only
• B. a bar of wrought iron only
• C. a battery
• D. (a), (b) and (c)

..................... (is) are from the uses of the electromagnet

• A. Moving the iron blocks in factories
• B. Making an electric mixer
• C. Making an electric generator
• D. (a) and (b)

the magnetic force of the electromagnet increase by ...............

• A. increasing the number of coil turns only
• B. increasing the intensity of the electric current only.
• C. cutting off the electric current
• D. both (a) and (b)

All the following devices have an electromagnet inside them except the ............

• electric bell
• television
• disc drive
• refrigerator

When an electric current passes through a coil twisted around a wrought iron bar, the wrought iron bar becomes a ............... magnet

• A. temporary
• B. permanent
• C. natural
• D. (a)and(b)