A uniform electric field E ⃗ \vec{E} E = -400√3 j ^ \hat{j} j ^ N C⁻¹ exists in a region. A positively charged particle is projected with initial speed 2√10 × 10⁶ m s⁻¹ towards target T as shown. Select the correct statement(s) about the projection angle and time of flight.
Physics · Electrostatic · Electric field intensity
JEE Advanced 2020

Question

A uniform electric field E ⃗ \vec{E} E = -400√3 j ^ \hat{j} j ^ N C⁻¹ exists in a region. A positively charged particle is projected with initial speed 2√10 × 10⁶ m s⁻¹ towards target T as shown. Select the correct statement(s) about the projection angle and time of flight.

Physics · Electrostatic · Electric field intensity

JEE Advanced 2020

G1 Physics · Accepted Answer

Step 1: In a uniform electric field the charge has constant acceleration 𝐚 = q𝐄/m, so the motion is mathematically identical to projectile motion. Step 2: Resolve the initial velocity and use x = uₓt, y = uᵧt + (1/2)at². Step 3: Impose the target/trajectory condition and solve for angle or time. Final: B: The particle hits T if projected at 30° or 60° from the horizontal.; C: The time to hit T can be 5√6 μs or 5√2 μs..

A uniform electric field E ⃗ \vec{E} E = -400√3 j ^ \hat{j} j ^ ​ N C⁻¹ exists in a region. A positively charged particle is projected with initial speed 2√10 × 10⁶ m s⁻¹ towards target T as shown. Select the correct statement(s) about the projection angle and time of flight.

A uniform electric field E ⃗ \vec{E} E = -400√3 j ^ \hat{j} j ^ N C⁻¹ exists in a region. A positively charged particle is projected with initial speed 2√10 × 10⁶ m s⁻¹ towards target T as shown. Select the correct statement(s) about the projection angle and time of flight.