Protons move rectilinearly in the region of space where there are uniform mutually perpendicular electric and magnetic fields `E` and `B`. The trajectory of protons lies in the plane xz as shown in the figure and forms an angle 9 with x-axis. Find the pitch of the helical trajectory along which the protons will move after the electric field is switched off.
![image](https://learnqa.s3.ap-south-1.amazonaws.com/images/16110469101585044977CjVZ6OxiuqJT5Ewk.png)