Question

The energy transformation in a mixie and a grinder is:
A) Electrical energy to heat energy
B) Electrical energy to mechanical energy
C) Electrical energy to sound energy
D) Electrical energy to light energy

Answer 1

A mixie and a grinder consist of a blade which crushes and mixes stuff as per our need. The blades are essentially connected to a motor which rotates. The energy required to rotate the motor is electrical energy. And the motion of the motor corresponds to the production of mechanical energy.

Complete step by step answer.
Step 1: Sketch a figure representing the arrangement of the circuit in which an electric motor works.

The above figure represents the arrangement for the working of an electric motor.

The electric motor works on the principle that when current is passed through a rectangular coil placed in a magnetic field, a force acts on the rectangular coil which causes it to rotate continuously.

Here when the current starts to flow through AB of the coil, the magnetic field generated would be from north to south and the force in AB is directed into the plane by Flemming’s left-hand rule, while that in CD is directed out of the plane. Thus half rotation of the rectangular coil is established.

Now for its full rotation, the direction of current has to be reversed. This is obtained by the commutator which consists of split rings and brushes. The rings spin as the coil rotates and the brushes will touch the gap between the rings when the coil becomes parallel to the magnetic field. The circuit will break. But the ring will keep moving due to inertia which causes the opposite end of the ring to connect with the positive end of the wire. The direction then gets reversed.

The rectangular coil ABCD will continue to rotate until the battery is switched off.

Thus it has converted the electrical energy into mechanical energy.

So the correct option is B.

Note: The absence of split rings will cause the coil to rotate half in the clockwise direction and the other half in the anticlockwise direction. It is the principle of energy conversion that resulted in the transformation of one form of energy into another form. Electric motors can use a DC power supply or an AC power supply. The alternate current periodically reverses its direction and changes its magnitude continuously with time.