unit 1 exam revision Flashcards
(28 cards)
What is the formula for calculating the maximum temperature (T) in terms of b?
T = b / 2.9 x 10^-3
The maximum temperature relates to the peak wavelength of emitted radiation from stars.
What is the relationship between speed of light (c), frequency (f), and wavelength (λ)?
c = f * λ
This fundamental equation applies to electromagnetic waves.
True or False: Stars with lower temperatures emit shorter peak wavelengths.
False
Lower temperatures correspond to longer peak wavelengths according to Wien’s Law.
What effect does the neutron have on the stability of a nucleus?
Increases repulsion and reduces stability
Neutrons affect the strong nuclear force and binding energy within the nucleus.
What is critical mass in the context of nuclear fission?
The minimum amount of fissile material required to sustain a chain reaction
Critical mass must include fissile nuclei to absorb emitted neutrons.
What is a challenge in the short-term storage of radioactive waste in Australia?
Limited availability of local disposal sites
This is a significant issue due to environmental and safety concerns.
Calculate the equivalent resistance (RT) of a circuit with resistances of 100Ω and 200Ω in series.
RT = 300Ω
The total resistance in a series circuit is the sum of individual resistances.
Fill in the blank: Electric current (I) can be calculated using the formula I = V / _______.
R
This formula relates voltage, current, and resistance in a circuit.
What happens to voltage in a series circuit?
Voltage is shared among components
Each component receives a portion of the total voltage supplied by the battery.
What is the principle behind total internal reflection?
Occurs when the angle of incidence exceeds the critical angle
This phenomenon is responsible for the formation of rainbows in diamonds.
What method of heat transfer occurs between the Sun and ice cream?
Radiation
This process involves electromagnetic waves transmitting energy without direct contact.
What is the impact of urbanization on local temperatures?
Increases temperature due to absorption of heat by materials
Urban materials like asphalt and concrete have lower specific heat capacities.
What is the result of nuclear fission?
Splitting of heavy nuclei into lighter daughter nuclei
Fission releases energy due to an increase in binding energy per nucleon.
What do gamma rays have that makes them highly penetrating?
Fast movement and negligible size
This allows gamma rays to pass through matter with minimal interaction.
How is the effective dose (ED) calculated for different organs?
ED = AD x weighting factor
This formula accounts for the varying sensitivity of different tissues to radiation.
What happens to binding energy when nuclei lighter than iron increase in mass?
Binding energy increases
This is a principle of nuclear physics related to stability.
What is the formula for calculating power (P) in terms of voltage (V) and resistance (R)?
P = V^2 / R
This formula is useful for calculating power in electrical circuits.
What characterizes non-ohmic devices?
Variable resistance depending on voltage or current
An example is an LED, which does not maintain constant resistance.
What is the significance of a circuit breaker in an electrical circuit?
Prevents excess current flow to avoid electrocution
Circuit breakers are crucial for safety in electrical appliances.
What is the characteristic of ohmic devices?
Ohmic devices have a constant resistance when either current or voltage is varied.
Can an LED be classified as an ohmic device? Why or why not?
No, an LED cannot be classified as an ohmic device because it does not have a constant resistance.
Calculate VR given the values 4.5 V and 1.8 V.
VR = 2.7 V
What is the formula to calculate resistance (R) using voltage (V) and current (I)?
R = V / I
If V is 2.7 V and I is 0.0139 A, what is the resistance R?
R = 194.24 Ω
