Electric Circuits Answers

A ball is thrown vertically upward and returns to its starting point 20 seconds later. Find its a) initial velocity; b) the maximum height it has reached.

A charged pith ball of mass 0.12 kg is suspended between parallel plates. The negative plate is on the bottom, and the plates are 0.5m apart. The pith ball is located halfway between the plates. Find a) the strength and direction of the electric field, b) the sign of the charge on the pith ball, c) the potential at the location of the pith ball, and d) what would happen if the pith ball were moved to a point 0.15 m above the negative plate. Show your work and explain your reasoning.

c)    If the area of a capacitor plates is squared three times and its square root distance tripled twice. What is the final value of its capacitance?   

b)   Three resistors, two of 4K8 both in parallel and a third one, are connected in series. A fourth resistor of 4M5 and fifth of twice the value of the third resistor together in series are connected in parallel with this circuit. The equivalent resistance of all the five resistors is given by 3K5.

                       i.        Calculate the value of the third and fifth resistors.

                      ii.        If a battery with e.m.f. of 20V is connected to this final circuit, calculate the current through the fifth resistor. Repeat for capacitors.            

Three charges lie along the x - axis as in figure. The positive charge q₁ = 9 μC is at x = 3 m, and the positive charge q₂ = 25 μC is at the origin.

Where must a charge q₃ be placed on the x - axis so that the resultant electric force on it is zero?

even the transistor able to do switching and amplification, why were the amplifiers introduce into the industry. justify the answer with the mathematical description