Advertisements
Advertisements
Question
Name five appliances or machines which use an electric motor.
Solution
Five appliances that use electric motor are:
(i) Electric fans
(ii) Washing machines
(iii) Refrigerators
(iv) Mixer and grinder
(v) Hair dryer
APPEARS IN
RELATED QUESTIONS
An electron emitter must have _____________ work function and ___________ melting point.
A force acts on a body and displaces it by a distance S in a direction at an angle θ with the direction of the force. What should be the value of θ to get the maximum positive work?
.A man raises a box of mass 50kg to a height of 2m in 20s, while another man raises the same box to the same height in 50s. Compare:
(i) the work done, and
(ii) the power developed by them.
A boy weighing 25 kgf climbs up from the first floor at height 3 m above the ground to the third floor at height 9m above the ground. What will be the increase in his gravitational potential energy? (Take g = 10 N kg -1)
State two disadvantages of producing hydroelectricity.
In which of the following case the work done by a force will be maximum : when the angle between the direction of force and direction of motion is 0° or 90°?
Name the physical quantity whose SI unit is Nm.
Write an expression for work done by a force depends?
An object is dropped from a height H. when is its
(i) P.E. maximum,
(ii) K.E. maximum,
(iii) P.E. = K.E.?
A boy pulls a box up to 10 m with a force of 5 kgf. Calculate the work done by him.
What do you understand by 'potential energy' and 'Kinetic energy'? Give three examples of each to illustrate your answer.
State the amount of work done by an object when it moves in a circular path for one complete rotation. Give a reason to justify your answer.
Explain, why submarines are able to dive underwater as well as a sail on the surface of the water?
An electric motor pump is 60% efficient and is rated 2.5 H.P. Calculate the maximum load it can lift through a height of 10m in 8 sec. (1 H.P. = 750 W).
A ______ should act on an object.
What is power? How do you differentiate kilowatt from kilowatt-hour? The Jog Falls in Karnataka state are nearly 20 m high. 2000 tonnes of waterfalls from it in a minute. Calculate the equivalent power if all this energy can be utilized? (g = 10 m s–2)