A charge of 25 nC is uniformly distributed along a circular arc (radius = 2.0 m) that is subtended by a 90-degree angle. What is the magnitude of the electric field at the center of the circle along which the arc lies?
a. 81 N/C
b. 61 N/C
c. 71 N/C
d. 51 N/C
e. 25 N/C
[Ques. 2] A charge (uniform linear density = 9.0 nC/m) is distributed along the x axis from x = 0 to x = 3.0 m. Determine the magnitude of the electric field at a point on the x axis with x = 4.0 m.
a. 81 N/C
b. 74 N/C
c. 61 N/C
d. 88 N/C
e. 20 N/C
[Ques. 3] A charge of 80 nC is uniformly distributed along the x axis from x = 0 to x = 2.0 m. Determine the magnitude of the electric field at a point on the x axis with x = 8.0 m.
a. 30 N/C
b. 15 N/C
c. 48 N/C
d. 90 N/C
e. 60 N/C
[Ques. 4] A 40-C charge is positioned on the x axis at x = 4.0 cm. Where should a 60-C charge be placed to produce a net electric field of zero at the origin?
a. 5.3 cm
b. 5.7 cm
c. 4.9 cm
d. 6.0 cm
e. +6.0 cm
[Ques. 5] A charge Q is placed on the x axis at x = +4.0 m. A second charge q is located at the origin. If Q = +75 nC and q = 8.0 nC, what is the magnitude of the electric field on the y axis at y = +3.0 m?
a. 19 N/C
b. 23 N/C
c. 32 N/C
d. 35 N/C
e. 21 N/C
[Ques. 6] A +20-nC point charge is placed on the x axis at x = 2.0 m, and a 25-nC point charge is placed on the y axis at y = 3.0 m. What is the direction of the electric field at the origin?
a. 209
b. 61
c. 29
d. 241
e. 151
[Ques. 7] A +15-nC point charge is placed on the x axis at x = 1.5 m, and a 20-nC charge is placed on the y axis at y = 2.0m. What is the magnitude of the electric field at the origin?
a. 105 N/C
b. 15 N/C
c. 75 N/C
d. 45 N/C
e. 60 N/C
[Ques. 8] A +2.0-nC point charge is placed at one corner of a square (1.5 m on a side), and a 3.0-nC charge is placed on a corner diagonally away from the first charge. What is the magnitude of the electric field at either of the two unoccupied corners?
a. 20 N/C
b. 14 N/C
c. 4.0 N/C
d. 12 N/C
e. 8.0 N/C
[Ques. 9] Imagine for a minute that the Moon is held in its orbit about the Earth by electrical forces rather than by gravitation. What electrical charges Q on the Earth and +Q on the Moon are necessary to hold the Moon in a circular orbit with a period of 27.3 days? The Earth-Moon distance is 384,000 km and the mass of the Moon is 7.35 1022 kg.
[Ques. 10] An alpha particle (charge = +2e) is sent at high speed toward a gold nucleus (charge +79e). What is the electrical force acting on the alpha particle when it is at a distance of 2 1014 m away from the gold nucleus? (e = 1.6 1019 C)