Brainscape's Knowledge GenomeTM

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


See full index

Physics > Wrong Answers From Pps > Flashcards

Wrong Answers From Pps Flashcards

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

What happens when a resultant force is applied to a moving object at a perpendicular direction to motion?

A

Object moves in a circle/changes direction

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

Define latent heat

A
  • Energy to break bonds

- with no change in KE, with no change in temperature: at a specified temperature

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

When waves go from deep to shallow, what happens to frequency, speed and wavelength of wave?

A

frequency always STAYS THE SAME
speed is reduced
wavelength is reduced/decreases

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

Describe how a transformer works?

A
  1. A voltage is induced
  2. Fewer/more coils in secondary so smaller/bigger voltage
  3. Field lines are cut
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Three ways in which energy is lost from transformer and from which part?

A
  • magnetic leakage from core
  • heat in coil, eddy currents in core
  • sound from core
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do you find pressure in terms of gas molecules in a closed box?

A

Total force divided by the area of the wall

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

What does virtual image mean?

A

It is formed behind object and lens and cannot be seen on a screen. No rays come from the image.

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

Why is a split ring commutator used?

A
  • To keep the two sides of coil in same direction

- So that rotation of coil doesn’t reverse its direction

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

When alpha and beta particles enter a magnetic field why are their paths curved?

A

The particles are charged so a force is created.

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

What is the radiation that reaches solar panels?

A

INFRA-RED radiation

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

Define total internal reflection

A
  • reflection in a more dense material where there is no refracted ray
  • all light in a more dense material is reflected
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define critical angle

A
  • the greatest angle of incidence at which refraction occurs

- when incident angle is refracted, refracted angle is 90 degrees

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

Define the DIRECTION of a magnetic field

A

The direction of force on a positive charge

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

What charge is produced on a metal pole joined to a lightning conductor and how does it become charged?

A

A positive charge. Electrons are repelled by the charged electrons in the thunderclouds so positive charges pulled closer and overall positive charge.

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

Three naturally occurring sources of background radiation?

A
  • Space
  • Air
  • Rocks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why does the count rate vary of radioactive sources than values predicted?

A

Due to random fluctuation/variation

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

What does a decrease in temperature to an aluminium block cause in terms of density?

A
  • Higher density

- due to separation of molecules decreasing: less KE so vibrate less so a smaller volume

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

Applications of microwaves?

A

Satellite communications,

Microwave ovens

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

What features does a graph need to have if it obeys Hooke’s law?

A

It is a straight line and it goes through the origin

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

Examples of man made devices that depend on moments?

A
  1. Spanner
  2. Scissor
  3. Steering wheel
  4. See-saw
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When a rod is not in equilibrium, what can you say about it?

A
  • more forces in one direction than another: resultant force

- there is a resultant moment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why does a water bottle sometimes collapse at different places?

A

At a higher place, pressure of air inside water bottle will EQUAL the pressure of air outside.
But when going to a different place, the bottle collapses as the pressure of air outside is GREATER than the inside of the bottle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What chases the reduced spacing of wavefronts after passing through a barrier?

A

The waves travel slower OR the water is shallower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

In a potential divider of a thermistor and variable resistor, what is the effect of changing current in the variable resistor?

A

The set value at which the component in the variable resistor circuit, comes on.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How to calculate final momentum of a truck after a truck has collided with another truck?

A

Momentum lost by truck 1 = momentum gain by truck 2

26
Q

When water is boiling, thermal energy is being applied to water. How does this energy affect molecules?

A

The molecules move apart - (as they are moving faster). The forces/bonds are BROKEN

27
Q

Describe how X-rays work in security application?

A

In airports. Radiation is emitted when a beam of electrons hit metal target.

28
Q

What assumption is made about a liquid when making a thermometer?

A

A liquid has uniform expansion - expands linearly

29
Q

How to make liquid more sensitive?

A

Larger bulb - increase in size of bulb
Decrease in tube diameter/capillaries
More liquid
Liquid with more expansion

30
Q

How to ensure thermometer is able to use same temperature range even if spacing of divisions of readings is increased?

A

Bulb must be longer?

31
Q

6 physical properties that may to be used to measure temperature?

A
  1. Resistance of metal
  2. Voltage of thermocouple
  3. Volume of gas
  4. Colour of metal
  5. Bending of bimetallic strip
  6. Amount of radiation
32
Q

Speed of sound in solid?

A

3000m/s

33
Q

Explain why sound waves are described as longitudinal?

A

Atoms oscillate in the same direction as the waves.

34
Q

In a coil of wire rotating steadily in a magnetic field, between poles of a magnet, what can be connected to make sure the current in a circuit connected is always in the same direction?

A

A rectifier /diode

35
Q

Symbol for finding temperature in specific heat capacity?

A

Use the theta symbol (O w a line through it) and always state…final temp -initial temp

36
Q

What is useful about having two stitches connected that alter circuit between two different wires?

A

When either switch is operated, the state of the lamp changes.

37
Q

Define electromagnetic induction

A

A process that causes a potential difference across a solenoid due to the movement of a nearby magnet

38
Q

What has to be two things have to be zero on an object for it to be in equilibrium?

A

The resultant and the moment/turning effect

39
Q

What kind of temp change is a very sensitive thermometer advantageous for?

A

Very small temp change

40
Q

Define dispersion

A

When a narrow beam of white light is passed through a prism and then splits into a range of colours called a spectrum

41
Q

Define an electric field

A

A region where a force acts upon an electric charge

42
Q

Describe the procedure of induction of a negative charge on a metal sphere?

A
  1. Bring a positively charged rod close to sphere
  2. Then touch the sphere with your finger or connect sphere to the earth
  3. Then remove charged rod
43
Q

Conclusions about atoms after Rutherford’s experiment?

A 
Atom is mostly empty space
Most of the mass of atoms is in the nucleus
The nucleus is very small
Charge of nucleus is overall positive
Charge of nucleus is v concentrated
44
Q

Why does a current get produced on the other secondary side of coil in a transformer?

A
  1. There is a magnetic field in the core
  2. The field is alternating/changing
  3. The field cuts/links with the secondary coil - the secondary coil cuts the field lines
  4. An EMF/voltage is induced
  5. So current produced in secondary coil circuit
45
Q

Explain in terms of force action, how acceleration of object varies during a fall from a tall building. (Including effects of air resistance)

A
  1. Air resistance force and opposite force downwards (due to gravity) present
  2. Acceleration at the start equals gravity so acceleration decreases as object falls
  3. Air resistance increases as speed increases
  4. Acceleration eventually reaches zero - terminal velocity
46
Q

4 actions to reduce thermal energy loss from an aluminium block?

A
  1. Insulate block
  2. Reduce draught
  3. Control temperature of the room
  4. Paint surface of block shiny
47
Q

How are EMF’s always induced?

A

By magnetic field lines being cut by coil turning

48
Q

Compare the deflections of alpha and beta particles in a vacuum between two strong poles of a magnet?

A
  1. They are deflected in opposite directions
  2. Beta particles are deflected more (lighter)
  3. Both paths are curves
49
Q

Define difference between specific heat capacity and just thermal capacity - AND thermal capacity equation?

A
  • Specific heat capacity is heat energy required to raise temperature of 1kg of a substance by 1 degree C.
  • Thermal capacity is heat energy required to raise temperature of substance by 1 degree C. EQUATION is C = mass x specific HC
50
Q

List of pieces of information needed to consider in order to make a decision about installing solar panels that are designed to heat water?

A
  • which direction roof faces
  • estimate output of panel
  • cost of panel
  • whether roof is shaded
  • household needs - whether household will use all hot water
51
Q

Define nuclear fusion ?

A

Atoms colliding and fusing together at high speeds to produce a different element- helium + ENERGY

52
Q

Use idea of momentum to explain how molecules exert a force in walls of cylinder?

A

The molecules collide with wall and these collisions cause a change in momentum.
The force is the rate of change of momentum

53
Q

Why would you need to use relays sometimes and what is the function of a relay?

A

Use relays when a certain object in circuit cannot provide enough power. Relays are small switch which can be used to turn on a current in a v powerful circuit.

54
Q

Why must relays be used sometimes?

A

When it is not possible to have a direct electrical connection between control circuit and output device - due to risk of damage to circuit from back EMF

55
Q

When a positively charged rod is brought close to metal painted tennis ball describe what happens to charges in metal painted tennis ball exactly?

A

The negative charges on the metal painted ball MOVE TOWARDS the rod and attract to positive charge

56
Q

What result from Rutherford experiment showed that atom consisted of v tiny charged core containing almost all the mass of the atom?

A

The fact that some alpha particles deflected greater than 90 degrees - deflected all the way back.

57
Q

Why is cooling curve steeper in a solid than a liquid as temperature decreases?

A

Specific heat capacity in solid is smaller than specific heat capacity in a liquid.

58
Q

Why is copper used in coil in transformers?

A

It has a very low resistance - it is a very good conductor of electricity

59
Q

Why is iron the core of transformer?

A

It is easily magnetised/demagnetised - ferrous but soft magnetic material

60
Q

Why is very high voltage used for transmission of large distances in transmission cables/pylons?

A
  • Very high voltage means a lower current.
  • This means more energy efficient as less heat/energy lost to surroundings.
  • Thin cables are suitable for low current - thin cables are cheaper

Physics (2 decks)

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