Circuits Exam

The base units in the SI system are

m, kg, s, A

The SI unit prefix pico is equal to a numeric factor of

*10-12

The current 1mA is the same as

*10−3A

The Voltage 10kV is the same as

10 · 10+3V

Resistors of the E6 series (20% tolerance) have the following values within the decade between 100 and 1000

10, 15, 22, 33, 47, 68

Joule's laws states power P=VI (Power is equal to voltage times current). For I=1A and V=1V, which of equation if correct?

P=1V*1A = 1W

The elements in a circuit have been labled as A: active B: passive C: passive Which of the following options will assure that the power is conserved in the circuit:

PA=+10W PB=+7W PC=+3W

The elements in a circuit have been labled as A: passive B: passive C: active Which of the following options will assure that the power is conserved in the circuit:

PA=-20W PB=+14W PC=-6W

An ideal current source is defined by the following sentence:

Provides the prescribed current at its terminals regardless of the circuit connected.

An ideal voltage source is defined by the following sentence:

Provides the prescribed voltage at its terminals regardless of the circuit connected.

If we replace the element(s) in a branch with a short circuit, the following statement is true:

R → 0, v=0 for any i.

If we replace the element(s) in a branch with an open circuit, the following statement is true:

R → ∞, i=0 for any v.

You have a Norton Current Source and its equivalent Thevenin Voltage Source given. The following statement is true

R(T)=1/G(N)

A practical voltage source is disconnected from any circuit. The following statement is true.

There will be no current through the internal resistance.

A passive circuit element

dissipates power.

The charge of an electron is given by qe = -1.602•10-19C. How many electrons will therefore provide a total charge of -1.602•10-16C?

1,000 electrons

The power rating of a 470Ω resistor carrying a current of 20mA should be

1/4W

The charge of an electron is given by qe = -1.602·10−19C. 25,000 electrons will therefore provide a total charge of

-4.005· 10−15

Given is a resistor R=1kΩ. There is a voltage drop of VR=10V across the resistor. Which power rating is needed for this resistor?

0.125W

Given is a resistor R=10kΩ. There is a current of IR=4mA across the resistor. Which power rating is needed for this resistor?

0.25W

A resistor of 6.8 kΩ is connected to a 6V battery pack. When measuring a current through the resistor which of the values do you approximately expect?

0.8mA

The voltage drop across a 2100W hairdryer that draws 16.8A is

125V

A toaster draws 15A from a 240V line. The resistance of the toaster is:

16 Ω

The current 2.5A is NOT the same as

2.5*10-3mA

A dieelectric material is charged by a current of 10A. Which charge will be accumulated in the material after 2s?

20C

The voltage drop across a 2100W hairdryer that draws 8.75A is

240V

A dieelectric material is charged by a current of 4A. A charge of 8C will be accumulated in the material after

2s

Resistors of the E12 series (10% tolerance) have the following values within the decade between 10 and 100: 10, 12, 15, 18, 22, 27, 33, 39, 47, 56, 68, 82 You have calculated a resistance of 30Ω. Which of the given resistor values do you choose?

33

A resistor draws 0.2mA from a 9V line. The resistance of the toaster is:

45kΩ

A dieelectric material is charged by a current. A charge of 20C is accumulated in the material after 4s. The charge current is:

5A

A dieelectric material is charged by a current of 10A. Which charge will be accumulated in the material after 0.5s?

5C

A resistor of 470 Ω draws a current of approximately 12 mA. When measuring voltage across the resistor what voltage do you expect?

6V

A dieelectric material is charged by a current of 3A. A charge of 21C will be accumulated in the material after

7s

An ideal voltage source is disconnected from any circuit. The following statement is true.

An ideal voltage source has no internal resistance.

You have given a long cylindrical resistor R1 = 73Ω. You are charged to build a second resistor R2 from the same material and of the same length but with twice the cross section. What will be the relationship between the resistance values of the two resistors?

R2 = 0.5 R1

The resitors R1=10Ω, R2=20Ω, R3=30Ω, and R4=40Ω are connected in series. What is the total equivalent resistance Req?

Req= 100Ω

The resitors R1=5Ω, R2=10Ω, R3=15Ω, and R4=20Ω are connected in series. What is the total equivalent resistance Req?

Req= 50Ω

There are N equal resistors connected in series. Each resistor has a resistance of R=30Ω. What is the total equivalent resistance Req if we have N=20 resistors?

Req= 600Ω

A practical current source is disconnected from any circuit. The following statement is true.

There is a current flowing through the internal resitance and therefore power used at all times.

The Norton Current and Thevenin Voltage are related via the following equation:

V(T)=R(T)*I(N)

There are N equal resistors connected in series. They are connected to a voltage source Vs=40V. Each resistor has a resistance of R=30Ω.What is the voltage Vn across one individual resistor if we have N=20 resistors?

Vn=2V

There are N equal resistors connected in series. They are connected to a voltage source Vs=60V. Each resistor has a resistance of R=30Ω.What is the voltage Vn across one individual resistor if we have N=20 resistors?

Vn=3V

To zero out a voltage source it must be replaced by

a short circuit.

The reciprocal of resistance is:

conductance.

A voltage source is

an active element.

If you set up an equation with Kirchhoff's Voltage Law (KVL) the convention is to count

an element voltage positive if you pass the element voltage from + to - and count the element voltage negative if you pass the element voltage from - to +.

A practical voltage source is described by

an ideal voltage source with an internal resistance in series

A practical voltage source is described by

an ideal voltage source with an internal resistance in series.

To zero out a current source it must be replaced by

an open circuit.

An active circuit element

generates power.

In the piece of circuit given below i1 = 2A and i2 = 4A. What is the value of i3?

i3 = 6A

To find the Norton Current, we have to

replace the load with a short circuit and compute the short circuit current.

The reciprocal of conductance is:

resistance.

A one-port network has

two terminals.

To compute the Thevenin Resistance

we compute the total resistance between the load terminals with the load removed and all independent sources turned off.

We can find the Norton Current

with any number of voltage and current sources present in the original circuit.

We can find the Thevenin Voltage

with any number of voltage and current sources present in the original circuit.