Mechanical Energy | MCQs

Explanation

A DC motor is an electrical machine that converts electrical energy into mechanical energy.

It uses electrical current to generate a magnetic field that interacts with the motor's magnets.

It causing the motor to rotate and produce mechanical energy.

Explanation

The potential energy (PE) of an object is calculated as:

PE = mass x gravity x height

= 1 kg x 10 m/s^2 x 1 m

= 10 Joule

So, the energy possessed by the body is 10 Joule.

Explanation

The kinetic energy (K.E) of an object is calculated as:

• K.E = (1/2) x mass x velocity^2
• = (1/2) x 1 kg x (1 m/s)^2
• = 0.5 Joule
• = 1/2 Joule

So, the kinetic energy of the body is 1/2 Joule or 0.5 Joule.

Explanation

• When Hyder hits the nail with a hammer, kinetic energy (the energy of motion) is involved as the hammer moves towards the nail.
• Sound energy is also involved as the hammer strikes the nail, producing a sound.
• However, electrical energy is not involved in this process.

Explanation

• An electric motor converts electrical energy into mechanical energy, producing motion or rotation.
• It uses electromagnetic forces to generate torque, which drives a shaft or other mechanical components.