Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MCAT physics & math > Circuits > Flashcards

Circuits Flashcards

You may prefer our related Brainscape-certified flashcards:
MCAT flashcards Physics 101 flashcards AP® Physics flashcards
1
Q

Current

A

Flow of positive charge–even though only negative charges are moving

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Metallic conductivity

A

Solid metals & molten forms of some salts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Electrolytic conductivity

A

conductivity in solutions

Depends on the concentration of the solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Conductance

A 
Reciprocal of resistance 
in siemens (S) or siemens/meter (S/m)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Magnitude of current

A

I=Q/Delta(t)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which way is current

A

Direction of the positive charge would flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

DC (direct current)

A

Charge flows in one direction only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

AC (Alternating current)

A

Current flow changes direction periodically

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Electromotive force (emf or e)

A

when no charge is moving between two terminals of a cell, they are at different potential values (in volts or J/C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Kirchhoff’s Laws

A

Conservation of charge & energy in a circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Kirchhoff’s Junction Rule

A

At any point or junction in a circuit, the sum of the currents directed into that point equals the sum of currents directed away from that point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Kirchhoff’s Loop Rule

A

Around any closed circuit loop, the sum of voltage sources will always be equal to the sum of the voltage (potential) drops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Resistance

A

The opposition within any material to the movement and flow of charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Resistance equation

A

R=pL/A

in Ohms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Resistivity

A

Intrinsic resistance to current flow in material

in Ohm meters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens to resistance as temperature increases?

A

It increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Ohm’s Law

A

V=IR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Actual voltage supplied by a cell

A

V=E(cell) - ir(int

E(cell)= emf of the cell
i=current through cell
rint=internal resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the internal resistance when there is no current?

A

0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the voltage of a cell when it is open?

A

=emf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How does the voltage of a cell compare when the current is flowing to when its not?

A

Less voltage when it is flowing

22
Q

What kind of cell recharges

A

Electrolytic

From low to higher potential

23
Q

What kind of cell discharges

A

Galvanic (voltaic)

24
Q

Power of a resistor

A

Rate at which energy is dissipated by a resistor

25
Q

Power of a resistor equation

A

P= IV=I^2R=V^2/R

26
Q

How are resistances & voltages in series treated?

A

Additive voltage drops & resistance

27
Q

How are resistance & voltages in parallel treated?

A

All voltages are equal

Resistance is reciprocal added

28
Q

What is the effect of adding resistors in parallel?

A

Reducing resistance

29
Q

Capacitator

A

Hold charge at a particular voltage

30
Q

Capacitance

A

Charge (Q)/Potential difference (V)

31
Q

Parallel plate capacitance

A

C=eo(A/d)

32
Q

Uniform electric field equation

A

E=V/d

33
Q

What is the direction on capacitor plate?

A

From positive to negative plate

34
Q

Potential energy stored in a capacitor

A

U=1/2CV^2

35
Q

Dielectric material

A

Insulation, introduced between capacitator plates & will increase the capacitance by a factor call the dielectric constant (k)

36
Q

Capacitance due to a dielectric material

A

C’=kC

37
Q

Can a dielectric material decrease the capacitance?

A

No, k is never less than 1

38
Q

Where does increase in capacitance come from in isolated (no circuit capacitators?

A

Decrease in voltage

39
Q

Where does increased capacitance come from in a capacitator in a circuit?

A

Increase in stored charge on the capacitator

40
Q

What stays constant in an isolated capacitator?

A

Charge

41
Q

What stays constant in a capacitaotr in a circuit?

A

Voltage

42
Q

What happens to capacitators in series?

A

Decrease capacitance
Reciprocal effect
Total voltage=sum of all voltages

43
Q

What happens to capacitators in parallel?

A

Addition of all capacitances

Voltages all equal to the source voltage

44
Q

Anmeter

A

Used to measure current (low resistance & voltage drop)

Placed in series with the point

45
Q

Voltmeter

A

Measure voltage drop across two points, wired in parallel to two points (infinite resistance)

46
Q

Ohmmeter

A

Doesn’t require a circuit to be active
Have their own battery of a voltage & finding current to find resistance
Wired in series of two points

47
Q

How is current calculated with resistors in series?

A

All currents are equal

48
Q

How is current calculated with resistors in parallel?

A

All currents are added

49
Q

What is the potential difference around a loop?

A

0 V

Kirchoff’s Loop Rule states that voltage gained by the battery will be used up by the resistors

50
Q

How to find electromotive force?

A

Voltage across terminals of battery when no current is flowing

Use V=e-ir(int)

MCAT physics & math (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions