Exam

Question 1

What is electrical circuit?

Answer 1

an electric network within which at least one closed path exists and around which electric charge may flow. Connected by conducting wires

Question 2

What is electrical current?

Answer 2

the rate at which charge passes through an area, such as the cross-sectional area of a wire.

Question 3

What is the fundamental electric quantity?

Answer 3

Charge (Coulomb)

Question 4

Units for current

Answer 4

1 ampere (A) = 1 coulomb/second (C/s).

Question 5

__ is required to move charge between two nodes in a circuit

Answer 5

Work

Question 6

What is electrical voltage?

Answer 6

Energy (in joules) per unit charge (1 coulomb) needed to move charge from one node to the other

Potential Difference

Question 7

Voltage Units

Answer 7

1 volt (V) = 1 joules/coulomb (J/C)

Question 8

What is a Reference node or Ground?

Answer 8

a specific, and usually clearly marked, node in
many circuits. Earth ground is always chosen as the
reference node because the earth’s potential is relatively stable and uniform due to its ability to store and distribute large quantities of charge.

Question 9

The danger from electrical shock depends on:

Answer 9

• the amount of the shocking current through the body,
• the duration of the shocking current through the body,
• the path of the shocking current through the body.

Question 10

Ideal voltage and current sources

Answer 10

“COME BACK”

Question 11

Passive Convention

Answer 11

• Assign a current through each passive element in a circuit. The direction of each current be assumed arbitrarily
• Assign a voltage across the element such that assigned current through the element is directed from high to low potential

Question 12

What is Electrical power? (units)

Answer 12

Current times Voltage (Joules per second; Watts (W))

Question 13

Conservation of Energy in Circuits

Answer 13

• Requires that the total power associated with the circuit be zero

Question 14

Positive power indicates that the element is either _ energy.

Answer 14

dissipating or storing

Question 15

What is electrical Resistance?

Answer 15

When charge flows through a wire or circuit element, it encounters resistance

Question 16

Electrical Resistance Equation

Answer 16

R = (ρ * l)/A

R = l / (σ * A)

* where ρ and σ are the material properties
resistivity and conductivity

Question 17

Electrical Resistance Units

Answer 17

Ohms (Ω)

Question 18

Ohms Law

Answer 18

The voltage across an ideal resistor is directly proportional to the current through it

V = R x i

Question 19

In a series circuit…

Answer 19

• The current is the same everywhere
• V = V1 + V2 + V3 +…
• Equivalent Resistance = Req = R1 + R2 + R3 +…

Question 20

In a parallel circuit…

Answer 20

• The volatge is the sane everywhere
• i = i1 + i2 + i3
• Equivalent Resistance = 1/Req = 1/R1 + 1/R2 + 1/R3 +…

Question 21

Passive vs. Active Components

Answer 21

Passive:
* Resistor
* Capacitor
* Inductor

Active:
* Diode
* Transistor

Question 22

Semiconductors

Answer 22

Silicon and germanium, from group IV of the periodic table whose conductivity is much weaker than that of a typical conductor but significantly stronger than that of a typical insulator.

Question 23

Semiconductor devices: Transistor

Answer 23

• A three-terminal semiconductor device that can perform two functions that are fundamental to the design of electronic circuits: amplification and switching.
• Amplification consists of using an external power source to produce a scaled reproduction of a signal (linear).
• Switching consists of using a relatively small input current or voltage to control a larger output current or voltage (nonlinear)

Question 24

Semiconductor devices: Diode

Answer 24

When sections of n- and p-type material are brought in contact to form a pn junction.

Question 25

p-type

Answer 25

Semiconductors doped with acceptor elements: holes are the majority charge carriers, and free electrons are the minority charge carriers

Question 26

n-type

Answer 26

semiconductors doped with donor elements: free electrons are the majority charge carriers, and holes are the minority charge carriers