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Fall 2015 PHYS1302. Exam 1. Chap19-22 Cheung. Special Code: 10
1. The force on positive charge q1 due to positive charge q2 points in the positive y direction. Which
statement is true regarding the force on charge q2:
(a) It points in the positive y direction with a different magnitude.
(b) It points in the positive y direction with the same magnitude.
(c) It points in the negative y direction with a different magnitude.
(d) It points in negative y direction with the same magnitude.
Answer d.
2. Due to a point charge, the magnitude of the electric field is 0.35 V/m at a distance of 0.40 m. Determine
the magnitude of the charge:
(a) 6.2 x10-12 C
(b) 1.6 x10-11 C
(c) 7.6 x10-10 C
(d) 2.9 x10-9 C
Answer a
3. The flux perpendicular to a closed surface is 5.0 Nm2/C. Determine the magnitude of the charge it
encloses:
(a). 9.1x10-12 C
(b). 4.4x10-11 C
(c). 3.3x1010 C
(d). 5.7x1011 C
Answer b
4. The electric potential at x=3m is 8 V and at x=5m is 16 V. Determine the direction and magnitude of the
electric field:
(a) 4 V/m, negative x direction
(b) 4 V/m, positive x direction
(c) 16 V/m, negative x direction
(d) 16 V/m, positive x direction
Answer a
5. A capacitor is charged, and the battery is disconnected. A dielectric material inserted between the plates
of this capacitor will serve what role?
(a) Increases the capacitance by decreasing the charge on each plate.
(b) Increases the capacitance by increasing the charge on each plate.
(c) Increases the capacitance by decreasing the potential difference.
(d) Increases the capacitance by increasing the potential difference.
Answer c
6. There is a potential difference of 12 V across a 4 Ω resistor. Determine the current:
(a) 3 A
(b) 4 A
(c) 24 A
(d) 48 A
Answer a
