Problem 3.
What must the charge (sign and magnitude) of a particle of mass 5 g be for it to remain stationary when placed in a downwarddirected electric field of magnitude 800 N/C?
Solution
Problem 4.
What is the magnitude of an electric field in which the electric force on a proton is equal in magnitude to its weight?
Solution
Problem 5.
A particle has a charge of 8.00 nC. Find the magnitude and direction of the electric field due to this particle at a point 0.5 m directly above it.
Solution
Problem 6.
Two particles having charges of 0.70 nC and 12 nC are separated by a distance of 2 m. At what point along the line connecting the two charges is the net electric field due to the two charges equal to zero?
Solution
Problem 10.
A thin disk with a circular hole at its center has inner radius a nd outer radius . The disk has a uniform positive surgace charge density on its surface. The disk lies in the yz plane, with its center at the origin. For an arbitrary point on the x axis (the axis of the disk) find the magnitude of the electric field.
Solution
Problem 11.
A thin disk with a circular hole at its center has inner radius a nd outer radius . The disk has a uniform positive surgace charge density on its surface. The disk lies in the yz plane, with its center at the origin.
A point particle with mass m and negative charge q is free to move along the x axis (but cannot move off the axis). The particle is originally placed at rest at x=0.01 and released. Find the frequency of oscillations.
Solution
Problem 14.
Each of the protons in a particle beam has a kinetic energy of . What are the magnitude and direction of the electric field that will stop these protons in a distance of 2 m?
Solution
Problem 15.
Two identical spheres are each attached to a rope of length 1 m and hung from a common point. Each sphere has mass 1 kg. The radius of each sphere is very small compared to the distance between the spheres, so they may be treated as point charges. The spheres have positive charges. The spheres are in equilibrium and each rope makes an angle 30 degrees with the vertical. Find the tension of the ropes.
Solution
Problem 16.
A solid metal sphere with radius 0.75 m carries a net charge of 0.13 nC. Find the magnitude of the electric field at the following locations:
a) at a point 0.15 m outside the surface of the sphere.
b) at a point outside the sphere, 0.1 m below the surface.
Solution
Problem 17.
How many excess electrons must be added to an isolated spherical conductor 27 cm in diameter to produce an electric field of 1450 N/C just outside the surface?
Solution
Problem 31.
In a Millikan oil drop experiment a student sprayed oil droplets with a density of between two horizontal parallel plates that were 6.0 cm apart. The student adjusted the potential difference between the plates to 5000 V so that one of the drops became stationary. The diameter of this drop was measured to be . What was the magnitude of the charge on the drop.
Solution
Problem 32.
You want to create an electric field at location . Where would you place a proton to produce this filed at the origin? Instead of a proton, where would you place an electron to produce this filed at the origin?
Solution
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