JEE Main202228 Jul 2022Evening ShiftPhysicsElectrostaticsActual
A uniform electric field E = 8 m e V m - 1 is created between two parallel plates of length 1 m as shown in figure, (where m = mass of electron and e = charge of electron). An electron enters the field symmetrically between the plates with a speed of 2 m s - 1 . The angle of the deviation θ of the path of the electron as it comes out of the field will be _____ .
Options
- Atan - 1 4
- Btan - 1 2
- Ctan - 1 1 3
- Dtan - 1 3
Correct answer
B. tan - 1 2
Step-by-step solution
Time taken by the electron to cross will be, t = 1 v x = 1 2   s . Acceleration of the electron along y axis a g = F m = E e m = 8 m e × e m = 8   m   s - 2 v y of the electron when it has crossed the capacitor will be, v y = a y t = 8 × 1 2 = 4   m   s - 1 Therefore, tan θ = v y v x = 4 2 = 2 ⇒ θ = tan - 1 2