Electricity Exam Review #2
Due: 3-8-212
1. Calculate the following for the circuit below.
20V
5
10
a) Calculate the current through the circuit.(4.16A)
b) The voltage drop across each resistor.(14V and 6V)
c) The current through each resistor.(2.8A, 1.4A, 2.08A, .2.08A)
2. Three 20resistors are hooked up to a 60V battery.
a) How much power will the resistors take if they are hooked up in parallel?(540W)
b) How much power will the resistors take if they are hooked up in series?(60W)
3. A wire has a current of 9.5amps and a voltage of 19.4 volts.
a) How many electrons pass through this light bulb in 4.75 minutes?(1.7x1022)
b) What is the resistance of the wire?(2.04 ohms)
c) What is the power rating of this wire?(184.3 watts)
d) How much energy will pass through this wire in 4.75 minutes?(5.22x104j)
4. A wire has a current of 13.65amps and a voltage of 4.55 volts.
a) How many electrons pass through this light bulb in 5 minutes?(2.56x1022)
b) What is the resistance of the wire?(.33 ohms)
5. A iron nucleus has 26 protons.
a) What is the charge of the nucleus?(4.16x10-18C)
b) An iron atom has 26 electrons. Calculate the force between the all the electrons and all the protons in
one iron atom assuming the average distance is 1.35x10-10m.(-8.55x10-6N)
6. A +6C charge is placed a distance x from a +1.5C charge. Draw the electric involving these two charges.
7. If the distance between two equally charged spheres is increased by a factor of 5, by what factor would the force
change?
8. For the following circuit:
20V15V
2
a) In which direction will the current flow and why?
b) What's the overall emf?(5V)
c) What's the current in the circuit?(0.5A)
d)If the 20V battery is turned around, what would the new emf and current be?(35V,3.5A)
9) An electric field has a magnitude of 3.0 N/m at a distance of 60 cm from a point charge. What is the
charge?(120pC)
10) Calculate the total capacitance for the circuit if C1 = 20F, C2 = 30F C3 = 10F, and C4 = 20F.(18.67F)
C1
C3

C2
C4
a
b
11) The following questions relate to the circuit in 10.
a) Do the electrons flow from a to b or b to a? Explain.
b) Do all of the electrons flowing through this circuit pass through point a? Explain.
c) Do all of the electrons flowing through this circuit pass through point b? Explain.
12) A light bulb has a power rating of 125 watts and a current of 13.8amps flowing through it.
a) How much energy does the light bulb use in 2 hours?(9.0x10 5j)
b) What is the voltage of this system?(9.06volts)
c) How many electrons pass through this light bulb in 2 hours?(6.21x10 23)
d) What is the resistance of this light bulb?(.66 ohms)