11PHYS > UNIT 1 > Flashcards

UNIT 1 Flashcards

(57 cards)

Study These Flashcards
1
Q

Define electric charge.

A

a fundamental property of matter that causes it to experience a force when placed in an electromagnetic field

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

What amount of charge is assigned to each: proton, neutron, electron? (both in qe and Coulombs)

A

Proton - +1qe, 1.6 x 10^-19C
Neutron - 0, 0C
Electron - -1qe, -1.6 x 10^-19C

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

State the formula linking no. of elementary charges, total charge (C) and elementary charge (C).

A

np OR ne = excess charge (C) / 1.6 x 10^-19

n = Q/qe

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

State the law of conservation of charge.

A

Charge can move but cannot be created or destroyed.

CHARGE IS ALWAYS CONSERVED

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

What is 1qe in C?

A

1.6 x 10^-19C

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

Define voltage

A

also called electric potential, it is the measure of electric potential energy per unit charge, measured in Joules per Coulomb.

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

Define Volts

A

a unit of voltage(electric potential), equivalent to 1J/C

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

Define electric current (also state symbol and units)

A

the rate of movement of charge carriers from one part of a conductor to another (Symbol = I, Units = A)

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

Explain conventional current

A

the direction of current flowing from the +ve power source terminal to the -ve, as opposed to the actual direction of electron flow, -ve to +ve

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

Explain the difference between DC and AC

A

DC (Direct Current) flows in one constant direction, like a battery powering a device.
AC (Alternating Current) changes direction back and forth rapidly, like the electricity from a wall socket.

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

Explain how a circuit works simply

A

In a circuit, charge carriers (usually electrons) have electric potential energy provided by a power source (like a battery). As these carriers move through the circuit, they transfer their potential energy to components (like lights, motors, or heaters), doing work such as producing light, motion, or heat. The battery keeps supplying energy, pushing the carriers around the circuit.

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

How are ammeters connected in circuits? Why? Why wouldn’t you connect them alternatively?

A

Ammeters are connected in series with the component being measured because they have very low resistance and need the full current to flow through them for an accurate reading. Connecting an ammeter in parallel would create a short circuit, bypassing the component and potentially damaging the ammeter or the circuit due to the excessive current flow.

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

How are measurement uncertainties decided for digital and analogue devices?

A

Digital - +- the smallest increment

Analogue - +- 1/2 the smallest increment

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

State the formula linking charge, time, current

A

I=q/t

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

Explain qualitatively why the separation of electric charge produces an electric potential difference.

A

Regions of opposite charge create an electric field.

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

State Ohm’s Law

A

V=IR (and simply rearrange)

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

What is the difference between ohmic and non-ohmic resistors?

A

Ohmic resistors follow Ohm’s Law (voltage is proportional to current), while non-ohmic resistors do not maintain a linear relationship between voltage and current.

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

Define electrical resistance, giving unit and formula for 1 unit.

A

The opposition to the flow of current, measure in Ohms (1 Ohm = 1V/A)

Dependent on length, area and material (resistivity).

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

Define a Nuclide

A

a particular kind of nucleus with a definite combination of protons and neutrons

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

Define strong nuclear force

A

force that holds protons and neutrons tightly together in the nucleus of an atom, overcoming the repulsive force between positively charged protons.

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

State Kirchoff’s current law

A

Kirchhoff’s Current Law (KCL):
The total current entering a node in a circuit equals the total current leaving the node.
(Charge is conserved.)

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

State kirchoff’s voltage law

A

Kirchhoff’s Voltage Law (KVL):
The sum of all voltages around a closed loop in a circuit is zero.
(Energy is conserved.)

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

Explain why nuclides are/aren’t stable

Study These Flashcards
A

Nuclide stability results from the strong nuclear force overcoming electrostatic repulsion between protons at very short distances, with the right balance of neutrons helping to maintain this stability–too many, and strong nuclear force cant hold together, too few, and proton like charges repel.

24
Q

Explain natural radioactive decay in terms of stability

Study These Flashcards
A

Natural radioactive decay happens when an unstable nucleus changes into a more stable one by releasing particles or energy,

25
What is ionisation ability?
If a radioactive particle ionises an atom, it means it knocks out one or more electrons, turning the atom into a charged ion.
26
Alpha particle properties:
-helium nucleus ^2v2He -charge: 2+ -mass: 4 amu -penetrating ability: low - stopped by paper/skin -ionising ability - very high
27
Beta -ve particle properties
-fast-moving electron emitted by a neutron -charge: 1- -mass: 1/1800amu -penetrating ability: intermediate, stopped by Al sheet -ionising ability: intermediate
28
Beta +ve particle properties
-fast-moving positron emitted by a proton -charge: 1+ -mass: 1/1800amu -penetrating ability: intermediate, stopped by Al sheet -ionising ability: intermediate
29
Gamma radiation properties
-high frequency/energy electromagnetic wave (EMR) (photon) -charge: 0 -mass: 0, energy only -penetrating ability - very high - needs 2" lead. -ionising power: very low, only when electrons get mad "excited"
30
What types of radiation result from excess protons, neutrons or mass:
Excess protons often cause beta plus (β⁺) decay, excess neutrons lead to beta minus (β⁻) decay, and excess mass (especially in heavy nuclei) usually results in alpha (α) decay, while gamma (γ) radiation often accompanies each of these to release extra energy, though ONLY STATE IT WHEN SPECIFIED) Note that nuclear decay is statistical and random, and hence it is impossible to precisely predict decay patterns.
31
Describe the concept of a half-life.
A half-life is the time it takes for half of the atoms in a radioactive sample to decay.
32
Define transmutation
when the element species changes in a nuclear decay.
33
Why are neutrinos/antineutrinos produced in beta decay?
Neutrinos and antineutrinos are produced in beta decay to conserve energy, momentum, and angular momentum (spin), ensuring that these fundamental quantities remain balanced during the decay process.
34
What particle always accompanies in Beta -ve decay? Why?
An Antineutrino, ν̄e, to conserve energy, momentum, and angular momentum (spin)
35
What particle always accompanies in Beta +ve decay? Why?
A Neutrino, ve, to conserve energy, momentum, and angular momentum (spin)
36
At what point will a nuclide become stable?
Lead-208 is considered the general endpoint, but can vary.
37
Describe the concept of artificial transmutation
changing one element into another by bombarding its nucleus with particles like protons, neutrons, or alpha particles or deutrons, causing it to decay
38
Formula for half-lives and radioactive nuclei remaining:
N=Nv0 x (1/2)^n
39
What is mass defect? Why does it occur?
The difference in mass between the constituent particles (cp) and mass of a nuclide. cp > n Why? Because some mass is converted into binding energy.
40
How do you express binding energy in Joules?
ΔE=Δmc^2 NOTE: E in J, m in kg!!! c=speed of light in vaccuum (dont forget to square!)
41
How do you express binding energy in J/nucleon?
E/nucleon = E in joules / no. of nucelons
42
How do you express binding energy in electron volts eV?
use J to eV conversion (f.book)
43
Define binding energy
Binding energy is the energy required to break a nucleus into its individual protons and neutrons, or equivalently, the energy released when a nucleus is formed from these particles.
44
Describe the mass-energy equivalence relationship.
Mass-energy equivalence means that mass and energy are two forms of the same thing, related by the formula E=mc^2 which shows that a small amount of mass can be converted into a large amount of energy. It can just manifest itself differently at times.
45
Define nuclear fission.
Nuclear fission is the process where a heavy nucleus splits into two smaller nuclei, releasing neutrons and a large amount of energy. Nuclides with masses larger than Fe-56 (56) are more likely to undergo fission.
46
Define nuclear fusion.
Nuclear fusion is the process where two light atomic nuclei combine to form a heavier nucleus, releasing a large amount of energy. Nuclides with masses smaller than Fe-56 (56) are more likely to undergo fusion.
47
Explain how a neutron-induced fission reaction occurs, and how it can lead to a chain reaction.
A neutron-induced fission reaction occurs when a neutron hits a heavy nucleus (like uranium-235), causing it to split into smaller nuclei, release energy, and emit extra neutrons; these extra neutrons can then trigger more fission reactions in nearby nuclei, creating a chain reaction.
48
Explain fission using the "water drop" model.
In the water drop model, fission is like a vibrating liquid drop that becomes so distorted by a neutron’s impact that it splits into two smaller drops, releasing energy and more neutrons.
49
How is energy change calculated in nuclear fission?
Energy change in nuclear fission is calculated by finding the mass defect between the original nucleus (mr) and the fission products (mp), then converting that mass loss into energy using E=mc^2
50
How is energy per kg of reactant calculated for fission reactions?
Divide energy released in joules by the mass of the reactants in kg.
51
Fission and Fusion reactions both produce...
energy and thus are sources of power
52
Define a proton-proton fusion reaction.
A proton-proton fusion reaction is a nuclear process where two hydrogen nuclei (protons) combine to form a heavier nucleus, eventually producing helium. This is the main source of energy in stars.
53
How is energy change calculated in fusion reactions?
-find mass difference -convert to kg, then energy -state in relevant units
54
# Resistors can be used to... Resistors can be used to...
control current and divide voltage
55
Formula for series resistors
R1 + R2 + R3 ... + Rn
56
Formula for parallel resistors
1/Rt = 1/R1 + 1/R2 + 1/R3 ...
57
11PHYS
flashcards
Decks in class (2)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions