A small thin metal strip lies on the lower plate of a parallel-plate capacitor positioned horizontally. The voltage across the capacitor plates is increased gradually to a value at which the electric force acting on the strip becomes greater than the strip's weight and makes the strip move toward the upper plate. Does the force acting on the strip remain coust.anj during the lifting process?

A bob of mass m carrying a positive charge q is suspended from a light insulating string of length l inside a parallel plate capacitor with its plates making an angle beta with the horizontal as shown in figure. The plates of the capacitor are connected with a battery to establish an electric field E between the plates with its upper plate negatively charged. Find the period of small oscillations of the pendulum and the angle between the thread and vertical in equilibrium position of the bob

A partical having charge that of an electron and mass 1.6xx10^(-30) kg is projected with an initial speed u at the angle 45^(@) to the horizontal from the lower plate of a parallel-plate capacitor as shown in fig. The plates are suffiecienly long and have a separation of 2 cm, find the maximum value of the velocity of he particle so that it does not hit the upper plate. Take the electric field between the plates as 10^(3)Vm^(-1) directed upward.

An electron (charge = e, mass = m) is projected horizontally into a uniform electric field produced between two oppositely charged parallel plates, as shown in figure. The charge density on both plates is +- sigma C//m^2 and separation between them is d. You have to assume that only electric force acts on the electron and there is no field outside the plates. Initial velocity of the electron is u, parallel to the plates along the line bisecting the gap between the plates. Length of plates is 2L and there is a screen perpendicular to them at a distance L. (i) Find s if the electron hits the screen at a point that is at same height as the upper plate. (ii) Final the angle q that the velocity of the electron makes with the screen while it strikes it.

A parallel plate air capacitor is connected to a battery. If the plates of the capacitor are pulled farther apart, then state whether the following statements are true or false. a. Strength of the electric field inside the capacitor remains unchanged, if the battery is disconnected before pulling the plates. b. During the process, work is done by the external force applied to pull the plates irrespective of whether the battery is disconnected or not. c. Strain energy in the capacitor decreases if the battery remains connected. .

The space between the rectangular plates (with sides a and b ) of a parallel-plato capacitor (the distance between the plates is l) is filled with a solid dielectric whose dielectric constant is c. The capacitor is charged to a certain potential difference and disconnected from the voltage source. After that the dielectric is slowly moved out of the capacitor, which lTIOanS that the section x not filled with the dielectric gradually increases in size. How wi ll the potential difference between the plates and the surface charge densities on both parts of the capacitor (with and without the dielectric) change in the process?

Lower plate of a parallel plate capacitor is fixed on a horizontal insulating surface. The upper plate is suspended above it using on elastic cord of force constant K. The upper plate has negligible mass and area of each plate is A. When there is no charge on the plates the equilibrium separation between them is d. When a potential difference = V is applied between the plates the equilibrium separation changes to x. (a) Calculate V as a function of x. (b) Find the value of x for which V is maximum. Calculate the maximum value of V (= V_(max)) (c) What will happen if V gt V_(max) ? (d) Plot a rough graph showing variation of equilibrium separation (x) with V

A parallel-plate capacitor of consists of 26 metal strips, each of 3cmxx4cm , separated by mica sheets of dielectric constant 6 and uniform thickness 0.2 mm. find the capacitance.

Imagin a parallel plate capacitor with a charge + Q on one plate and -Q on the other. Initially, the plates are almost, but not quite, touching. The plates are gradually pulled apart to make the separation d. The separation d is small compared to dimensions of the plates and we can maintain that field between the plates is uniform. Area of each plate is A. (a) Write the energy stored in the electric field between the plates when separation between then is d. (b) Assuming that the energy calculated in part (a) can be attributed to the work done by the external agent in pulling the plates apart, calculate the electrostatic attraction force between the plates.