Electromagnetic Spectrum

The order of electromagnetic waves in increasing frequency: So, among the given options:
- Infrared comes before X-rays
- X-rays come before Gamma rays
Hence, correct increasing order is:

When a charged particle moves through crossed electric and magnetic fields, the particle moves undeflected when the electric force and magnetic force balance each other. The electric force is and the magnetic force is , where is the speed of the particle. For no deflection, we have:
Thus, the speed of the particle is .