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An electron falls from rest through a verticaldistance h in a uniform and vertically upwarddirected electric field E. The direction of electricalfield is now reversed, keeping its magnitude thesame. A proton is allowed to fall from rest inthrough the same vertical distance h. The time fallof the electron, in comparison to the time fall ofthe proton is :-​
  • a)
    smaller
  • b)
    5 times greater
  • c)
    10 times greater
  • d)
    equal
Correct answer is option 'A'. Can you explain this answer?
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An electron falls from rest through a verticaldistance h in a uniform ...
Explanation:

When an electron is placed in an upward directed uniform electric field, it experiences a force equal to -eE in the downward direction, where e is the charge of the electron and E is the electric field strength.

The acceleration experienced by the electron is given by a = F/m = (-eE)/m, where m is the mass of the electron. On solving, we get a = -eE/m.

Using the equations of motion, we can find the time taken by the electron to fall through the distance h:

h = (1/2)at² => t = sqrt(2h/a) = sqrt((2h*m)/(-eE))

When the direction of the electric field is reversed, the force experienced by the electron becomes eE in the upward direction. The acceleration experienced by the electron becomes a = eE/m, and using the same equations of motion, we can find the time taken by the electron to fall through the distance h:

h = (1/2)at² => t = sqrt(2h/a) = sqrt((2h*m)/(eE))

Comparing the two expressions for time, we can see that the time taken by the electron is smaller when the electric field is directed upwards than when it is directed downwards. This is because the acceleration of the electron is in the opposite direction to the direction of motion, which slows down the electron's fall.

The proton, being positively charged, experiences an upward force when placed in an upward directed electric field. Its acceleration is given by a = eE/m, where e is the charge of the proton and m is the mass of the proton. Using the same equations of motion, we can find the time taken by the proton to fall through the distance h:

h = (1/2)at² => t = sqrt(2h/a) = sqrt((2h*m)/(eE))

Comparing the expressions for time taken by the electron and the proton, we can see that the time taken by the electron is smaller than the time taken by the proton. This is because the acceleration experienced by the proton is in the same direction as the direction of motion, which increases the proton's fall.
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An electron falls from rest through a verticaldistance h in a uniform and vertically upwarddirected electric field E. The direction of electricalfield is now reversed, keeping its magnitude thesame. A proton is allowed to fall from rest inthrough the same vertical distance h. The time fallof the electron, in comparison to the time fall ofthe proton is :-​a)smallerb)5 times greaterc)10 times greaterd)equalCorrect answer is option 'A'. Can you explain this answer?
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An electron falls from rest through a verticaldistance h in a uniform and vertically upwarddirected electric field E. The direction of electricalfield is now reversed, keeping its magnitude thesame. A proton is allowed to fall from rest inthrough the same vertical distance h. The time fallof the electron, in comparison to the time fall ofthe proton is :-​a)smallerb)5 times greaterc)10 times greaterd)equalCorrect answer is option 'A'. Can you explain this answer? for NEET 2024 is part of NEET preparation. The Question and answers have been prepared according to the NEET exam syllabus. Information about An electron falls from rest through a verticaldistance h in a uniform and vertically upwarddirected electric field E. The direction of electricalfield is now reversed, keeping its magnitude thesame. A proton is allowed to fall from rest inthrough the same vertical distance h. The time fallof the electron, in comparison to the time fall ofthe proton is :-​a)smallerb)5 times greaterc)10 times greaterd)equalCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for NEET 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for An electron falls from rest through a verticaldistance h in a uniform and vertically upwarddirected electric field E. The direction of electricalfield is now reversed, keeping its magnitude thesame. A proton is allowed to fall from rest inthrough the same vertical distance h. The time fallof the electron, in comparison to the time fall ofthe proton is :-​a)smallerb)5 times greaterc)10 times greaterd)equalCorrect answer is option 'A'. Can you explain this answer?.
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