Menu

Physicshelpline

Solution Search

Comments

. : "Electrostatics"

Electrostatics: Capacitors

Q- Two capacitors C1 = 30 µF and C2 = 60 µF are connected in series with a 12 V battery. Find

(a) The charge on C1 and

(b) The potential difference across C2.

Solution:

Read more

Capacitor

Q- A capacitor stores 135 J of energy when it is charged to 300 V

(a) What is the capacitance of the capacitor?

(b) How much charge must be transferred from one plate to the other to store this energy? 

Solution:

Read more

Electrostatics: Electric Field

Q- Three charges are placed at the vertices of an equilateral triangle of side a = 6 cm. qA = +3 µC, qB = +3 µC, and qC = -3 µC.

(a) Find the x- and y- components of the electric force acting on qC

(b) Find the electric field at the position of qC due to qA and qB.

Solution:

Read more

Electrostatics: Coulomb's Law

Q- Two charges Qc and -Qc (Qc = 4 µC) are fixed on the x-axis at x = -6 cm and x = 6 cm, respectively. A third charge Qb = 5 µC is fixed at the origin. A particle with charge q = 0.5 µC and mass m = 6 g is placed on the y-axis at y = 14 cm and released. There is no gravity. Calculate the initial …

Read more

Electrostatics: Capacitors

Q- Determine the equivalent capacitance of the combination shown in figure where a = 10C and b = 45C

Solution:

Read more

Electrostatics: Coulomb's Law

Q- A rigid, insulating fiber if fixed vertically. A charge Qa = -7 µC is fixed to the fiber at some point. A bead with a hole drilled through its center is slipped over the fiber above Qa and is free to move along the fiber without friction. The mass of the bead is m = 160 g and its charge is Qb. A…

Read more

Capacitor

Q- Find the equivalent capacitance between points a and b in the combination of capacitors shown in Figure. C1 = 2.0 µF and C2 = 3.0 µF.

Solution:

Read more

Electrostatics: Field due to a charged cylinder

Q- A hollow cylinder of radius a and length L, open at its ends, carries a uniform surface charge density σ. Use the formula for electric field due to a thin uniformly charged ring; find the expression for the electric field at a point P on the axis of the cylinder at a distance b from its nearest …

Read more

Electrostatics: Potential and Field

Q- The potential at a point on the axis of a uniformly charged circular disk is given by

          

Where s is the surface charge density, r is the distance of the point from the center of the disk and ‘a’ is the radius of the disk. Find an expression for the electric field as a function…

Read more

Electrostatics: Potential

Q- In moving from point A to point B, an alpha particle lost 9.8*10-17 J of electric potential energy and gains an equal amount of kinetic energy. What is the potential difference between A and B?

Solution:

Read more

Electrostatics: Field and flux

Q- A +1 µC point charge is at the center of a cubical box 0.5m on an edge.

(a) Calculate the magnitude of the electric field at the center of each face.

(b) Compute the outward electric flux through each face of the box.

Solution: 

Read more

Electrostatics: Field

Q- An isolated charged conducting sphere of radius 15.0 cm creates an electric field of 4.90*104 N/C at a distance 22.0 cm from its center.

(a) What is its surface charge density?
(b) What is its capacitance?

Solution:

Read more

Electrostatics: Field

Q- Three point charges are aligned along the x axis as shown in Figure. Find the electric field at

(a) The position (2.00m, 0)

(b) The position (0, 2.00m).

Solution:

Read more

Electrostatics: Field

Q- Consider the rectangle below BCDE of length 24cm. and width 18cm. Position A is at the center of the rectangle. Point charges q1 = (+) 0.2 µC, q2 = (+) 0.8 µC and q3 = (-) 0.6 µC are placed at the corners B, C and D of the rectangle as shown. Find the magnitude and direction of the electric fie…

Read more

Capacitance

Q- A commercial capacitor is to be constructed as shown in Figure. This particular capacitor is made from two strips of aluminum foil separated by a strip of paraffin-coated paper. Each strip of foil and paper is 7.90 cm wide. The foil is 0.00400 mm thick, and the paper is 0.0250 mm thick and has a …

Read more

Electrostatics: Field and Potential

Q- Given two 2.00-mC charges, as shown in Figure and a positive test charge q = 1.28*10-18 C at the origin,

(a) What is the net force exerted by the two 2.00-mC charges on the test charge q?

(b) What is the electric field at the origin due to the two 2.00mC charges?

(c) What is the electri…

Read more

Electrostatics: Potential

Q- Two charges are fixed in place with a separation d. One charge is positive and has seven times (n = 7) the magnitude of the other charge, which is negative. The positive charge lies to the left of the negative charge. Relative to the negative charge, locate the two spots on the line through the c…

Read more

Electrostatics: Electric Flux

Q- Consider a closed triangular box resting within a horizontal electric field of magnitude E =7.80 X 104 N/C as shown in Figure. Calculate the electric flux through (a) the vertical rectangular surface, (b) the slanted surface, and (c) the entire surface of the box.

Solution:

Read more

Eletrostatics: Coulomb's law

Q- Two tiny identical metal balls each of mass 10g and carrying equal positive charges are suspended from a point by “weightless” insulated strings each of 1m length. The balls repel each other and come to an equilibrium position with each string making an angle of 370 to the vertical.
(a) Draw …

Read more

Electrostatics - Energy

Q- Two identical +7.5µC point charges are initially 5.5cm apart. If they are released at the same instant from rest, how fast will they be moving when they are very far apart? Assume they have identical masses of 1.0 mg.

Solution:

Read more