SHM, Waves, Thermo, E&M Practice Problem Workbook
SHM, Waves, Thermo, E&M Practice Problem Workbook
SHM, Waves, Thermo, E&M Practice Problem Workbook
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
MECHANICS PRACTICE PROBLEM SETS 40<br />
10.3 ELECTRICITY REVIEW<br />
1. Two charges are separated by 3.0 cm. Object A has a charge of + 6.0µC while<br />
object B has a charge of +3.0µC. What is the force on object A<br />
Answer: 180 N away from B<br />
2. A sphere with charge + 6.0µC is located near two other charged spheres. A -<br />
3.0µC sphere is located 40.0cm to the right and a + 1.5µC sphere is located 30.0<br />
cm directly underneath. Determine the net force (magnitude and direction) on the<br />
+ 6.0µC charge. Answer: 1.35 N at 42°<br />
3. A negative charge of 2.0 x 10 -8 C experiences a force of 0.060 N to the right in an<br />
electric field. What is the field magnitude and direction<br />
Answer: 3 x 10 6 N/C, to the left<br />
4. What is the magnitude and direction of the electric field at a point midway<br />
between a - 8.0µC and a + 6.0µC that are 4.0 cm apart.<br />
Answer: 3.15 x 10 8 N/C toward negative<br />
5. An electron acquires 3.45 x 10 -16 J of kinetic energy when it is accelerated by an<br />
electric field in a computer monitor from plate A to plate B. What is the potential<br />
difference between the plates and which plate has a higher potential<br />
Answer: 2.15 x 10 3 V; Plate B is higher<br />
6. Two parallel plates are connected to a 100-V power supply and are separated by<br />
an air gap. How small can the gap be if the air is not to exceed its breakdown<br />
value of E = 3 x 10 6 V/m<br />
Answer: 3.3 x 10 -5 m<br />
7. An automobile headlight with a resistance of 30 Ω is placed across a 12-V<br />
battery. What is the current through the circuit Answer: 0.40 A<br />
8. A bird stands on an electric transmission line carrying 2500 A. The resistance per<br />
meter of the line is 2.5 x 10 -5 Ω/m. If the bird’s feet are 4.0 cm apart, what voltage<br />
does the bird feel<br />
Answer: 0.0025 V<br />
9. What is the diameter of a 1.00-m length of tungsten wire whose resistance is 0.22<br />
Ω The resistivity of tungsten is 5.6 x 10 -8 Ω•m. Answer: 5.7 x 10 -4 m<br />
10. Suppose the resistance in a copper wire with a diameter of 1.02 mm carrying 1.67<br />
A has a resistance of 1.05 Ω at 20°C. What is the resistance at 0°C and 100°C if<br />
the temperature coefficient for copper is 0.00393°C -1 Answer: 0.97 Ω; 1.38 Ω<br />
11. What is the maximum voltage that can be applied to a 2.7-kΩ resistor rated at<br />
0.25 Watts Answer: 26 V<br />
Gamzon & Gregorian-Michaelsen 6/13/12
Change language