Brainscape's Knowledge GenomeTM

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


See full index

Physics Unit 2 > Circuits > Flashcards

Circuits Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
0
Q

A charged atom is called an…?

A

Ion. This can be made by taking away or adding electrons.

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

Rubbing a balloon charges it with…?

A

Static electricity. This charge makes the balloon attract to things.

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

Rubbing a polythene rod with a dry cloth transfers electrons to the surface atoms of the rod to the cloth so it becomes positively charged.

A

Rubbing a Perspex rod with a dry cloth transfers electrons from the surface atoms of the cloth to the rod so the cloth becomes negatively charged.

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

Learn electric circuit symbols.

A

Yes.

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

Current is a measure of…?

A

Rate of flow of charge

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

When a toe his switched on, millions of electrons pass through the bulb every second carrying a negative charge. Metals contain lots of electrons that move freely around them to hold positively and negatively charged particles together.

A

Yes.

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

Electric charge is measured in coulombs.

A current if one amp is a rate of flow of charge of one coulomb per second.

A

Yes.

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

Current (amps) = charge flow in coulombs/time taken in seconds

A

I = Q/T

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

Ammeters are connected I series and measures the current through components.

A

Voltage is measured in parallel with the bulb so it measures the potential difference across it.

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

Potential different = work done in joules/charge in coulombs

A

V = W/Q

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

Voltage = current x resistance

A

V = IR

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

If the current is directly proportional to the potential difference for a wire at constant temperature we say the component obeys…?

A

Ohm’s Law

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

Why is a wire an ohmic conductor?

A

Because its resistance is constant and reversing the potential difference makes no difference to the line on a current-potential difference graph.

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

In a filament bulb…

A
  • It is not an ohmic conductor
  • The line curves away from the current axis
  • The resistance of the metal filament increases as its temperature increases because ions in the metal filament vibrate more as the temperature increases so they resist the passage of electrons through the bulb
  • Resistance is always the same no matter which way the flow of charge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In a diode…

A
  • In the forward direction, the line curves towards the current axis so the current is not directly proportional to the potential difference and a diode is not an ohmic conductor
  • There is no current in the reverse direction so resistance in the reverse is much higher than in the forward direction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

In a thermistor…

A

If temperature is increased, resistance decreases

16
Q

In an LDR…

A

Resistance decreases when the light intensity on it increases

17
Q

In a series circuit…

A
  • The same current passed through all components in series with each other
  • The voltage is shared between components
  • Provided cells act in the same direction, the total potential difference if the cells is the sum if the potential difference of each cell
  • The total resistance of components is equal to the sum of the resistance of each component
18
Q

In a parallel circuit…

A
  • The total current is the sum of the current through each component
  • The potential difference across each component is the same because each electron will only pass through one component or the other
19
Q

Why is a cell necessary?

A

To push electrons around a complete circuit

20
Q

Why is a switch necessary?

A

To turn the current on or off.

21
Q

A bulb will emit light when current passes through it.

A

Yes.

22
Q

A diode allows light through in one direction only.

A

Yes.

23
Q

What does an LED do?

A

Emits light when current passes through it

24
Q

What is an ammeter used for?

A

To measure electric current

25
Q

A fixed resistor limits the current in a circuit. A variable resistor…?

A

Allows the current to be varied

26
Q

What is a fuse designed to do?

A

Melt when too much current passed through it, therefore braking the circuit.

27
Q

A heater is designed to transfer electrical energy to heat the surroundings.

A

Yes.

28
Q

What is a voltmeter used for?

A

To measure potential difference

Physics Unit 2 (4 decks)

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