Electrostatics ...

What is called electric energy tank

Two parallel infinite line charges + λ and –λ are placedwith a separation distance R in free space. The net electric field exactly mid-way between the two line charges is

Two small spheres of masses M₁ and M₂ are suspended by weightless insulating threads of lengths L₁ and L₂. The spheres carry charges Q₁ and Q₂ respectively. The spheres are suspended such that they are in level with one another and the threads are inclined to the vertical at angles of θ₁ and θ₂ as shown. Which one of the following conditions is essential, if θ₁ = θ₂ ?

Two identical positive charges are fixed on the y -axis at equal distances from the origin O. A negatively charged particle starts on the x-axis, at a large distance from O, moves along the x-axis, passes through O and moves far away from O. Its acceleration a is taken as positive along its direction of motion. The best graph between the particle's acceleration and its x-coordinate is represented by

A simple pendulum has a length l and the mass of the bob is m. The bob is given a charge q coulomb. The pendulum is suspended between the vertical plates of a charged parallel plate capacitor. If E is the electric field strength between the plates, the time period of the pendulum is given by

A cubical region of side a has its centre at the origin. It encloses three fixed point charges, - q at (0, a / 4, 0), + 3q and – q at (0, + a/ 4, 0). Choose the correct option(s).