Figure shows tracks of three charged particles crossing a uniform electrostatic field with same velocities along horizontal. Give the sign of the three charges. Which particle has the highest charge to mass ratio?

Options

A. 1 and 2 are negatively charged
3 positively charged

Third particle has highest charge to mass ratio
B. 1 and 2 are positively charged
3 positively charged

Third particle has highest charge to mass ratio
C. 1 and 2 are negatively charged
3 positively charged

second particle has highest charge to mass ratio
D. 1 and 2 are negatively charged
3 negatively charged

Third particle has highest charge to mass ratio

Answer

A

Explanation

Opposite charges attract each other and same charges repel each other. It can be observed that particles 1 and 2 both move towards the positively charged plate and repel away from the negatively charged plate. Hence, these two particles are negatively charged. It can also be observed that particle 3 moves towards the negatively charged plate and repels away from the positively charged plate. Hence, particle 3 is positively charged.
The charge to mass ratio (emf) is directly proportional to the displacement or amount of deflection for a given velocity. Since the deflection of particle 3 is the maximum, it has the highest charge to mass ratio.