7. Exercises VII

1. Name some devices in which electric motors are used. 

 

An electric motor is a type of rotating devicelinear device. It converts electrical energy to mechanical energymechanical energy to electrical energy.

 

(Drag and Drop the devices in which electric motors used)

 

 

  

 

2. A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is -
(i) pushed into the coil,

(ii) withdrawn from inside the coil,
(iii) held stationary inside the coil?

 

i. If a bar magnet is pushed into the coil of insulated copper wire, the magnetic field lines associated with the coil changesdoes not change, then the galvanometer shows no deflectionshows deflection as current is not inducedcurrent is induced in the coil.

 

ii.When the bar magnet is withdrawn from the coil, the galvanometer shows deflectionshows no deflection again but now to the same sideopposite side because the induced current is in theopposite directionsame direction .

 

iii. When the bar magnet is held stationary inside the coil, the galvanometer shows no deflectionshows deflection due to no induced currentinduced current.