EGR203 Electronic Circuits Assignment 1
- Determine the total charge entering a circuit element between
t = 1 s and t = 2 s if the current passing through the
element is i = 3t2 (amps)
- Suppose that the cost of electrical energy is $0.094 per kilowatt
hour (Dayton Power and Light, January 2013) and that your electric bill
for 30 days is $70 (power usage only, not including other charges or taxes).
Assume that the power delivered
is constant over the entire 30 days. What is the power in watts? If a
voltage of 110 V supplies this power, what current flows? Part of your
electrical load is a 60-W light that is on continuously. By what
percentage can your energy consumption be reduced by turning this
light off?
- A typical alkaline 9-V battery that costs $1.95 is capable of
delivering a current of 50 mA for a period of 10 hours. Determine the
cost of the energy delivered by this battery per kilowatt hour.
Compare to the $0.094 per kilowatt hour for energy purchased from
Dayton Power and Light.
- Your resistor is color coded green-blue-red. What is its
nominal resistance?
- Suppose we measured a resistance of
about 1.4 Ω across a graphite stick, used calipers to
measure the cross-section of the stick (7 mm by 5 mm) and measured
the distance between the multimeter test leads (54 mm). Based on these
measurements, calculate the bulk resistivity of the graphic stick.
- Given a resistor of 110 Ω connected to a
12 V battery, find the power absorbed by the resistor. What are the
consequences if the resistor is rated at one-quarter watt?
- Suppose we have a 220-Ω resistor rated at one-half watt.
What is the maximum voltage we can apply to the resistor without
exceeding its power rating?
- Suppose your multimeter is fused for 300 mA. You want to
measure current through a resistor via a 9-volt battery. What is the
minimum resistance such that the current is less than 200 mA?
- A typical lead acid storage battery has a mass of 30 kg.
Starting from a fully charged state, it can supply 5 A for 24 hours
with a terminal voltage of 12 V before it is discharged.
a. If the energy stored in the fully charged battery is used
to lift the battery with 100-percent efficiency, what height is
attained? Assume that the acceleration due to gravity is 9.8
m/s2 and us constant with height. b. If the stored
energy is used to accelerate the battery with 100-percent efficiency,
what velocity is attained? c. Gasoline contains about
4.5 × 107 J/kg. Compare this with the energy content
per unit mass for the fully charged battery.
- A typical “deep-cycle” battery (used for electric
trolling motors for fishing boats) is capable of delivering 12.6 V
and 10 A for a period of 10 hours. How much charge (in columbs) flows
through the battery in this interval? How much energy does the
battery deliver?
- A copper wire has a diameter of 2.05 mm and carries a current
of 5 A due solely to electrons. (these values are common in
residential wiring.) Each electron is has a charge of
of -1.6 × 10-19 C. Given that the free electron
(those electrons capable of moving through the copper) concentration
in copper is 1029 electrons/m3, find the average
velocity of the electrons in the wire.
- Given two resistors, R1 = 1.5 kΩ and R2= 2.7 kΩ,
find the resistance in series and in parallel.
Maintained by John
Loomis, last updated 19 January 2013