Answer
Correct Answer is B(to change direct current into alternating current)
Explanation
commutation
The main aim of commutation is to maintain the torque acting on armature of DC motros in the same direction.
commutator a switch which is used to convert the direction of flow of electric current it is connected to the armature of DC motor.
In DC motors, voltage across the armature is alternating in nature. The direction of this current is reverses by Commutator when armature of DC motors passes through magnetic neutral axis to maintain the unidirectional. Hence, commutator is used to change direct current into alternating current.
Answer:
The height of the liquid column doesn't affect the pressure on top pressure ina liquid is affected by the weight of the above it
Answer:
A
Explanation:
So a pulse is a part of a mechanical wave, and mechanical waves are energy transfer trough some medium, in this case a stretched spring. So the correct answer is (A) energy only. The pulse cant be transferred into mass.
Answer:
4.71m/s
Explanation:
Average speed = Total distance travelled ÷ Total time taken.
80/17=4.71
4.71m/s
Answer:
a sound wave is an electromagnetic wave
