Physics Electrostatics Level: High School
Express tension T on the string in terms of the known quantities .1. T= mg/tan theta
2. T= mg/sin theta
3. T=gl sin theta
4. T=mg cos theta
5. T=mg/cos theta
6. T=mg tan theta
7. T= mgl tan theta
8. T= mgl/sin theta
9. T= mg/sin theta
10. None of these
Physics Electrostatics Level: High School
A small 2 g plastic bag is suspended by a 27.4 cm long string in a uniform electric field 1160 N/C as in the figure at ‘click here’ . The ball is in equilibrium when the string makes a(n) 23 degree angle with the vertical . The acceleration of gravity is 9.8 m/s^2 . Use a free body diagram to find the relationship among theta , m g and qE .1. cos theta = qE/mg
2. sin theta = qE/mg
3. cos theta = mg/qE
4. sin theta = mg /qE
5.tan theta = mg/qE
6.tan theta = qE/ mg
What is the net charge q on the ball ? Answer in units of µC .
Physics Electrostatics Level: High School
Consider a square with side a . Four charges ¨Cq, +q , +q and ¨Cq are placed at the corners A,B,C, and D respectively (see the figure at ¡®click here¡¯) The magnitude of the electric field Enoat (noat=0) at the center O is given by1. E noat = ¡Ì2 kq/a^2
2. E noat = 1/4¡Ì2 kq/a^2
3. E noat = 1/2¡Ì2 kq/a^2
4. E noat = 1/3¡Ì2 kq/a^2
5. E noat = 1/¡Ì2 kq/a^2
6. E noat = 3¡Ì2 kq/a^2
7. E noat = 3 kq/a^2
8. E noat = 4¡Ì2 kq/a^2
9. E noat = 2¡Ì2 kq/a^2
10.E noat = kq/a^2
Here ¡Ì means square root
Physics Electrostatics Level: High School
Coulomb constant is 8.98755 x 10^9 N m^2/ C^2. The 1.49 µC charged is at the origin and a -8.21µC charge is 10 cm to the right , as shown in the figure at “click here” Identify the direction of E in the region II (0 1. down 2. all possibilities : right, left, or zero 3. left 4. right 5. None of these 6. up 1. down 2. all possibilities : right, left, or zero 3. left 4. right. 5.None of these 6. up
Physics Electrostatics Level: High School
A uniformly charged circular are AB of radius R is shown in the figure at “click here” . It covers a quarter of a circle and it is located in the second quadrant. The total charge on the arc is Q>0 . The direction of the electric field vector E at the origin , due to the charge distribution is1. along the negative x-axis
2. in quadrant II
3. along the positive x-axis.
4. along the positive y-axis.
5. in quadrant I.
6. in quadrant IV
7. in quadrant III
8. along the negative y-axis.
Physics Electrostatics Level: High School
The diagram at “click here” shows an isolated , positive charge Q , where point B is twice as far away from Q as point A.1. EA/ EB = 2/1
2. EA/ EB = 1/1
3. EA/ EB =8/1
4. EA/ EB =4/1
5. EA/ EB =1/2
Physics Electrostatics Level: High School
Three point-charges ( +q , -q , and +q ) are placed at the vertices of an equilateral triangle (see figure at gclick hereh)The magnitude of the electric force on the charge at the bottom left-hand vertex of the triangle due to the other two charges is given by .
(1)F = ã2/3 k q^2/a^2
(2)F = 2/ã3 k q^2/a^2
(3)F = 1/2 k q^2/a^2
(4)F = 3/ã2 k q^2/a^2
(5)F = 1/(2ã3) k q^2/a^2
(6)F = ã2 k q^2/a^2
(7)F = 1/ã2 k q^2/a^2
(8)F = ã3/2 k q^2/a^2
(9)F = ã3 k q^2/a^2
(10)F = k q^2/a^2
Physics Electrostatics Level: High School
Two identical small charged sphere hang in equilibrium with equal masses a shown in the figure at “click here” . The length of the strings are equal and the angle with the vertical is identical .The acceleration of gravity is 9.8 m/ s^2 and the value of Coulomb’s constant is 8.98755 x 10^9 Nm^2/C^2 .
Find the magnitude of the charge on each sphere . Answer in units of C .
Physics Electrostatics Level: High School
Two charged particle of equal magnitude (-Q and -Q) are fixed at opposite corners of a square that lies in a plane ( see figure which is shown at “click here”). A test charge –q is placed at a third corner .What is the direction of the force on the test charge due to the two other charges
1. north west
2. north east
3. towards east
4. south west
5. south east
6. towards north
7. towards west
8. towards south
Physics Electrostatics Level: High School
A solid conducting sphere is given a positive charge Q . How is the charge Q distributed in or on the sphere ?(1) It is concentrated at the centre of the sphere .
(2) It is uniformly distributed throughout the sphere
(3) It is uniformly distributed on the surface of the sphere only .
(4) Its density increases radially outward from the center .
(5) Its density decreases radially outward from the center.
Physics Electrostatics Level: High School
A plastic rod is rubbed against a wool shirt, thereby acquiring a charge of -4.9µC. They charge on an electron is 1.6 x 10^-19 C. How many electrons are transferred from the wool shirt to the plastic rod ?
Physics Electrostatics Level: High School
You have a light weight spring whose unstretched length is 4.0 cm. You are curious to see if you can use this spring to measure charge .First, you attach one end of the spring to the ceiling and hang a 1.0 g mass from it. This stretches the spring to a length of 5.0 cm . You then attach two small plastic beads to the opposite ends of the spring, lay the spring on a frictionless table, and give each plastic bead the same charge. This stretches the spring to a length of 4.5 cm.(a) What is the magnitude of the charge (in nC) on each bead ?
Physics Misc Topic Level: Misc Level
What are the total positive and total negative charge in a nickel that is electrically neutral ? The mass of a nickel atom is 9.74 x 10^-25 kg .
Physics Electrostatics Level: High School
What are the total positive and total negative charge in a nickel that is electrically neutral ? The mass of a nickel atom is 9.74 x 10^-25 kg .
Physics Electrostatics Level: High School
What are the electric fields at points 1 and 2 in the triangle which is shown at “click here”