Join 60,000+ competitive exam aspirants
or with email
Your Cart
Subtotal₹0
Total₹0
Examoogle • User • info@examoogle.com • EE-2024-8821
Chapter 1 of 12 • Page 1 of 248🔒 Protected PDF • Watermarked
Join 60,000+ competitive exam aspirants
An electron moving with a velocity of 3×106 m/s enters an electric field of 1000 V/m. Calculate the acceleration of the electron. (Charge = 1.6×10−19 C, mass = 9.1×10−31 kg)
1.75 ×10¹⁴ m/s2
3.5 ×10¹⁴ m/s2
0.8 ×10¹⁴ m/s2
5.2 ×10¹⁴ m/s2
75 ×10¹⁴ m/s2
The acceleration of a charged particle in a uniform electric field is determined by the force exerted on it by the field, which leads to Newtonian acceleration. By applying Newton's Second Law (F=ma) and the definition of electric force (F=qE), the acceleration is calculated as a=mqE.
The acceleration of a charged particle in a uniform electric field is determined by the force exerted on it by the field, which leads to Newtonian acceleration. By applying Newton's Second Law (F=ma) and the definition of electric force (F=qE), the acceleration is calculated as a=mqE.
Think of the electric field as a constant wind blowing across an open field. Just as the wind exerts a steady force on a ball regardless of its current speed, the electric field exerts a constant force on the electron, causing it to accelerate in the direction of the field (or opposite to it, depending on the charge).
F-qE: 'Force equals q times E' (Force is the product of charge and electric field strength).
F=qE — The force exerted by an electric field on a charge
a=mqE — The acceleration of the particle derived from Newton's Second Law
When an electron with charge q is placed in an electric field E, it experiences a force given by F=qE. According to Newton's Second Law, this force produces an acceleration a=mF=mqE. The initial velocity does not affect the magnitude of the acceleration caused by the electric field, provided the field is uniform.
The acceleration is independent of the electron's velocity.
The electron experiences force opposite to the direction of the electric field because it is negatively charged.
Calculated value: a=9.1×10−31 kg(1.6×10−19 C)×(1000 V/m)≈1.758×1014 m/s2.
Uniform acceleration allows for predictable motion in electron tubes.
High velocity electrons may eventually exhibit relativistic effects, making simple Newtonian physics less accurate.
Cathode Ray Tubes (CRT)
Particle accelerators
The mass of an electron me is approximately 9.11×10−31 kg.
Option B, C, and D are incorrect because they result from erroneous arithmetic or incorrect use of constants.
A is correct — The acceleration is calculated using a=mqE, resulting in 1.75×1014 m/s2.
In physics problems involving charged particles, always verify if the velocity is needed for the calculation; here, it is a distractor as acceleration depends only on q, E, and m.