Advertisements
Advertisements
प्रश्न
A proton is kept at rest. A positively charged particle is released from rest at a distance d in its field. Consider two experiments; one in which the charged particle is also a proton and in another, a positron. In the same time t, the work done on the two moving charged particles is ______.
पर्याय
same as the same force law is involved in the two experiments.
less for the case of a positron, as the positron moves away more rapidly and the force on it weakens.
more for the case of a positron, as the positron moves away a larger distance.
same as the work done by charged particle on the stationary proton.
Advertisements
उत्तर
A proton is kept at rest. A positively charged particle is released from rest at a distance d in its field. Consider two experiments; one in which the charged particle is also a proton and in another, a positron. In the same time t, the work done on the two moving charged particles is more for the case of a positron, as the positron moves away a larger distance.
Explanation:
The force between two protons is equal to the force between proton and a positron because their charges are the same. As the mass of positron is much lesser than the proton, (1/1840 times) it moves away through a much larger distance compared to the proton.
Change in their momentum will be the same. So, the velocity of a lighter particle will be greater than that of a heavier particle. So, the positron is moved through a larger distance.
As work done = force x distance. As forces are the same in case of proton and positron but distance moved by positron is larger, hence, work done will be more.
APPEARS IN
संबंधित प्रश्न
Write an expression for the work done when a force is acting on an object in the direction of its displacement.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A sailboat is moving due to wind energy.
What is the work done by the moon when it revolves around the earth?
State the S.I. unit of energy.
A body, when acted upon by a force of 10 kgf, moves to a distance 0.5 m in the direction of force. Find the work done by the force. Take 1 kgf = 10 N.
In which of the following cases, is work being done?
(i) A man pushing a wall.
(ii) a coolie standing with a load of 12 kgf on his head.
(iii) A boy climbing up a staircase.
MULTIPLE CHOICE TYPE
In an electric cell which in use, the change in energy is from:
How many watts equal one horse power?
Give two examples of couple action in our daily life.
P, Q and R are three forces which act as shown in fig.

The point O lies in the same plane. Given, P = Q = R = 10N
(i) Which force has the least moment about O? Give a reason.
(ii)Which force has the greatest moment about O? Give a reason.
A uniform circular motion is an accelerated motion. Justify it.
Name the type of energy possessed by a
(i) stretched catapult (ii) hot iron
(iii) wound up clock
In what way does an ‘Ideal machine’ differ from a ‘Practical machine’?
A coolie is pushing a box weighing 1500 N up an inclined plane 7.5 m long on to a platform, 2.5 m above the ground.
(i) Calculate the mechanical advantage of the inclined plane. (ii) Calculate the effort applied by the coolie.
(iii) In actual practice, the coolie needs to apply more effort than what is calculated. Give one reason why you think the coolie needs to apply more effort.
If a ball is dropped on the sloping roof of a house, it acquires ______ and falls on the ground. That is the transformation of ______ energy into ______ energy takes place.
(kinetic, potential, motion)
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)
