Sample Exam I

1. Two point charges are separated by a distance d and feel a force F. What would the force be if the two 
charges are moved a distance 4d apart?
(a) 8N (b) 16N (c) 0.25N (d) 0.75N (e) 0.06 N

2.  Electric field lines  
(a) circle clockwise around positive point charges.
(b) move toward negative point charges.
(c) move outward from negative point charges.
(d) circle counterclockwise around positive charges.

3. If the radius of the wire is doubled, the resistance of the will be
a.  quadrupled.             b.  doubled.      c.  cut in half.    d.  remain unchanged.

4.  A 24 ohms resistor is connected to a 12-V battery. How much current flows through the resistor?
(a) 0.5A  (b) 0.25A  (c) 2A  (d) 1.5A

5. The Voltage delivered to a circuit is 220 V and the current, which results, is 1/2 A. 
The power delivered to the circuit is
(a) 660 W  (b) 73 W  (c) 110 W   (d) 220 W

6.  An electrons was moved 2 cm on the surface of the equipotential that has potential of 2 V. 
Work done on the electron is,
(a) 2 J              (b) 4 J              (c) zero            (d) -2 J

7. If the distance between the plates of a capacitor is doubled, the electric field will be
(a) doubled       (b) remain unchanged    (c)  decreased by half   (a) increased

8.  Calculate the electrical potential for a charge 3.6x10 –9 C at a spot that is 0.25m away from a charge. 
Find the magnitude of the charge.

9. Two charges q1 = 3 C is located at x= 2 cm from the origin and other charge q2 = -6 C is located at x= 4 cm. 
What is the total electrical potential due both charges at the origin?

10. A capacitor is to be constructed with parallel plates separated by 3.0 mm and is to have a capacitance 
of 3.0x10–9 F. Calculate the area of each plate.

11.  What is the equivalent capacitance of a series combination of 6, 12, and 36 Farad capacitors?

12. At 283 0C the resistance of a copper wire was doubled from its original resistance at 20 0 C. 
What is its temperature coefficient of resistivity?