dc theory lesson 3 test
Use the product-sum method to solve for total resistance in a circuit containing one 25-ohm and one 15-ohm resistor.
(R1xR2)/(R1+R2) (25x15)/25+15) 9.375
What is the compression ratio for an engine if each cylinder has a maximum volume of 500 cubic centimeters and a minimum volume of 50 cubic centimeters?
10:1
The weight of outlet boxes is proportional to the volume of boxes involved. If 400 boxes weigh 120 pounds, how much would 500 boxes weigh?
150
For two resistors to be in parallel with each other in a circuit, there must be ? current path(s).
2
State the product over sum formula for determining total resistance in parallel circuits containing two unequal resistances.
Rt=R1xR2/R1+R2
How many 60-watt lamps could be connected in parallel on a 15-amp, 120-volt circuit without exceeding 80% of the rating of the circuit?
24 look at picture then look at the next picture for next question
Solve for total circuit resistance in the circuit
46.15
Two lamps are connected in parallel across a 120-volt source. Each lamp has an internal resistance of 96 ohms. What is the equivalent circuit resistance?
48 Rt=R/N 96/2
The ratio of the speeds of pulleys is inversely proportional to the ratio of their diameters. The speed reduction required on a pulley and belt drive is 4 to 1. If the drive is 4 inches in diameter, what size would be required for the driven pulley?
D1/D2=S2/S1 4/X=1/4 16
Determine the voltage across resistor R2.
Er1=Ir1xR1 0.5x3 15V
What is the voltage of the source if each resistor has a resistance of 100 Ω and the current through each resistor is 3 amps?
Er1=Ir1xR1 3x100 300
If two 6-volt sources are connected in parallel to supply a 24-ohm load, how much current will flow in the circuit?
It=Et/Rt 6/24 0.25 A
What is the formula for finding total current in a parallel circuit when branch currents are known?
It=I1+I2+I3+.....In
How much power would be consumed in a parallel circuit that has a source voltage of 300 volts and a total circuit current of 4.2 amps?
Pt = Et × It 300x4.2 1,260
Three lamps, with wattages of 100 watts, 250 watts and 60 watts, are connected on a circuit. What is the total power consumed by the circuit when all lamps are operating?
Pt = PL1 + PL2 + PL3 = 100 + 250 + 60 = 410 W
Which of the following is NOT one of the three rules that are to be applied when solving problems involving direct or inverse proportions?
Solve by subtraction answers are Solve by cross-multiplication Set up the proportion Substitute the values
The total resistance of any number of parallel resistances, all having the same value, is equal to the value of any one of the resistors divided by the total number of resistors.
True
In a parallel circuit, the entire ? is dropped across each branch.
applied voltage
In a proportion, the ? of the equivalent fractions are always equal.
cross products
A parallel circuit is one in which there is more than one point where the ? divides and follows different paths.
current
Circuit components that are connected in such a way that they provide different current paths are said to be connected in parallel.
false
Direct proportion is two quantities related and dependent in such a way that as one increases the other decreases, and conversely, as one decreases the other increases.
false
When resistors are connected in parallel, the total resistance of the circuit will be greater than the smallest resistor value in the circuit.
false
Adding additional resistors in parallel with those resistors already existing in a parallel connected circuit will always increase the total resistance.
false Adding additional resistors in parallel with those resistors already existing in a parallel connected circuit will always decrease the total resistance.
In a parallel circuit with a single power source, the current that leaves and re-enters the power source is called the ?
total current
A break in any branch of a parallel circuit will cause a decrease in the total current of the circuit.
true
By definition, a ratio initially takes on the form of a fraction.
true
Parallel circuits may contain more than one voltage source.
true
The indirect method is used to determine total power in a parallel circuit from the sum of the individual power consumptions of the loads in the circuit.
true
The voltage applied to each load in a parallel circuit is the same.
true
Two resistors of equal value are connected in parallel with each other. The power dissipated by the two resistors will be equal to the sum of the power dissipated by each resistor.
true
Power sources connected in parallel should have the same ? rating.
voltage
