Q. 9

A particle moves in a region having a uniform magnetic field and a parallel, uniform electric field. At some instant, the velocity of the particle is perpendicular to the field direction. The path of the particle will be
A. a straight line

B. a circle

C. a helix with uniform pitch

D. a helix with non-uniform pitch

Answer :

The region has a uniform magnetic field and an electric field.

Formula used: Lorentz’s force is given by



Where F is Lorentz’s force


q is electric charge


E is electric field strength


B is magnetic field strength


V is velocity


The electric field will accelerate the particle to move in the direction of the magnetic field. Magnetic field will always change the direction of velocity of a particle. Because of these the particle will move in a helix path with non-uniformity. So option D is correct.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Equation of electric and magnetic fieldEquation of electric and magnetic fieldEquation of electric and magnetic field52 mins
Magnetic force on moving charge particle in magnetic field | QuizMagnetic force on moving charge particle in magnetic field | QuizMagnetic force on moving charge particle in magnetic field | Quiz32 mins
Magnetic force on moving charge particle in magnetic fieldMagnetic force on moving charge particle in magnetic fieldMagnetic force on moving charge particle in magnetic field44 mins
Magnetic field due to current carrying straight wireMagnetic field due to current carrying straight wireMagnetic field due to current carrying straight wire37 mins
Magnetic field due to current carrying circular loopMagnetic field due to current carrying circular loopMagnetic field due to current carrying circular loop36 mins
Superfast Revision of Potential & Potenial Energy (Theory + Interactive Quiz)Superfast Revision of Potential & Potenial Energy (Theory + Interactive Quiz)Superfast Revision of Potential & Potenial Energy (Theory + Interactive Quiz)47 mins
Few Applications of Gauss's lawFew Applications of Gauss's lawFew Applications of Gauss's law54 mins
Gain Confidence on Magnetic Effects of Current with QuestionsGain Confidence on Magnetic Effects of Current with QuestionsGain Confidence on Magnetic Effects of Current with Questions41 mins
Electric field inside cavityElectric field inside cavityElectric field inside cavity37 mins
Test Your Knowledge of Electric Charge & Coulomb's LawTest Your Knowledge of Electric Charge & Coulomb's LawTest Your Knowledge of Electric Charge & Coulomb's Law47 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses
RELATED QUESTIONS :