Topic: Electric field, field lines, field of point charge· Electrostatics

An electron falls from rest through a vertical distance h in a uniform and vertically upward directed electric field E. The direction of electric field is now reversed, keeping its magnitude the same. A proton is allowed to fall from rest in it throu…

An electron falls from rest through a vertical distance h in a uniform and vertically upward directed electric field E. The direction of electric field is now reversed, keeping its magnitude the same. A proton is allowed to fall from rest in it through the same vertical distance h. The time of fall of the electron, in comparison to the time of fall of the proton is

1. smaller

2. 10 times greater

3. 5 times greater

4. equal

Doubtly Asked 30 Oct 2026 NEET UG 2018 Practice test neet Save WhatsApp Report

1 answer

Best answer

Answer: 1. smaller

The force magnitude is \(eE\) for both particles, so \(a=\dfrac{eE}{m}\). Fall distance \(h=\tfrac12at^2\) gives \(t=\sqrt{\dfrac{2h}{a}}\).

The electron has a much smaller mass (about 1/1836 of the proton's), so its acceleration is far larger and its time is smaller. Field reversal makes both accelerate downward. (Gravity is neglected compared with the electric force.)

The time of the electron is smaller.

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

Was this answer helpful?

An electron falls from rest through a vertical distance h in a uniform and vertically upward directed electric field E. The direction of electric field is now reversed, keeping its magnitude the same. A proton is allowed to fall from rest in it throu…

1 answer

Your answer