Applications of Electromagnetism Quiz (Theory)

The becomes strongly magnetised.The bar is up.

The pulls the copper bar to the right.

The break the circuit and the current stops flowing.

1. turns in electromagnet coil.
2. move the electromagnet to the iron bar 
3. use an iron bar of a weight

The   carrying coil of wire in the field experiences a

 ( current directions is to field)

If the current , the direction of the force on the wire reverses.

The cone vibrates and .

The   carrying coil of wire in the field experiences a .

The on the coil changes ( backwards and forwards ) causing vibration

When the cone vibrates, molecules in front of it also .

Thus a sound wave travels in the form of and rarefactions.

The note has intensity.

A sound is heard.

A relay is used, e.g. In the motor circuit.

As the is too , handling it directly using a switch is .

A flows in the , so it becomes .

The in the coil the pivoted iron armature.

The armature about the pivot and causes the contacts to close.

The of the LDR .

The on the core are . The armature still to the core.

Iron is easily magnetised and , while steel magnetism.

With  iron, when the switch is off, the armature does not stay to the core.

 The   of attraction of the is too . 

  strongly .

The iron bar is .

The   pulls the bar.

The contacts  

 Iron is easily   and ,while steel retains .

The core   are . The (armature still)     to the (core).

Series with C and  

The   of the LDR .

The note has  

  The  cone ,the air   also .

 A    wave travels in the form of and .

The   reverses the direction of the   on the wire. 

The cone back and .

  turns in  coil

electromagnet   to the iron bar 

iron bar of a   weight