Explanation​:
373$K$ is the boiling point of water. Temperature does not change until all water is boiled. B and C show temperature change at $t=0$. D is not compatible with the question. You might have seen graphs that resemble options B and D in this context, they are there to distract you.

Explanation​:
The average kinetic energy doubles which means that the temperature doubles. To maintain constant pressure, volume would have to double.

Since the number of molecules also doubles, volume would have to double again to maintain constant pressure.

Thus the volume must get 4 times larger from pV=nRT

The change of state will occur at the same temperature as the original graph but take less time to complete.

Explanation​:
To calculate $n$, the student would rearrange the formula to get

• n=PV/RT​

In both operations, the percentage uncertainty must be added, therefore the correct answer is C (2 % + 6 % + 1 % = 9 %)

Explanation​:

From the circuit symbols in the data booklet, component A is a heating element.

When current flows in the circuit, the heating element will increase in temperature and the resistance will increase. This will increase the total resistance of the circuit and result in a decrease in the current due to the relationship I=V/R​.

Explanation​:

Uranium-235 is a rare radioactive isotope on Earth, extracted from uranium ores. The available uranium is limited and will be depleted in time. Biomass will replenish in a human lifetime, so is considered renewable.

Explanation​:
Temperature appears to be doubled; but that is using the celsius scale. Absolute temperature is not doubled. So, $D$ is incorrect.

Volume cannot change, since the container's volume is fixed. The number of moles cannot change since the gas is enclosed in the container.

Hence, pressure is proportional to absolute temperature:

p2/p=[273+542]/[73+27] ⇒p2=1.09p

Explanation​:

Solar constant (S) is the intensity of sun light at the orbit of the planet. For Earth, at a distance of 1AU from the sun, it is 1.36×10^3 W m^−2

Intensity is inversely proportional to the square of the distance from the source: I∝1/d^2

$\therefore$ Intensity at a distance 30 times as far will be 30^2 (=900) times weaker.

SNeptune=1360/900=1.5 W m^−2

Explanation​:
Non-renewable sources are sources where the rate of replenishment is much longer than a human lifespan. Examples include nuclear, coal, oil, and natural gas. Therefore, the answer is A.

Explanation​:
Using V=W/q​ from the data booklet, we find that the charge q passing through the bulb in 2 seconds equals W/V=1000 J/200 V=5C.

Since I=Δq/Δt​, the current in the bulb is 5C/2 s=2.5 A

Explanation​:
Average kinetic energy increases as the temperature increases and stays constant during the vapourisation process. Moreover, average kinetic energy is zero at absolute zero (−273oC) temperature, which is not the case for water (0−100oC)

Explanation​:

The energy $E$ required to completely melt each substance is given by

• E=mL

where $m$ is the mass of the substance and $L$ is the specific latent heat of fusion.

Therefore, for a given power $P$, the duration tmelt​ of the plateau obeys the equation

tmelt=mL/P​

The two substances have equal values of $m$ and $P$, meaning that since Substance $A$ has a higher tmelt​ value than Substance $B$, it also possesses a higher $L$ value. Hence, Statement III is incorrect.

The rates of temperature change before and after melting are related to the specific heat capacity $c$ via the expression

• E = mcΔT
• PΔt=mcΔT
• ΔTΔt=Pmc​

The gradient of the graph is therefore inversely proportional to $c$.

In both solid and liquid state, Substance $A$ exhibits a higher value of ΔTΔt​ than Substance $B$, meaning that has a lower value of $c$. Hence, Statement I is correct.

Furthermore, for each substance, the gradient of the graph is lower in the liquid phase than in the solid phase, which means that after melting $c$ increases and Statement II is correct.

Explanation​:

Ice has half the specific heat capacity of liquid water and the rate of energy loss is constant. Therefore, after freezing the temperature of the system decreases at twice the rate compared to when cooling in the liquid state.

Explanation​:
E=mcΔTE=Pt

Pt=mcΔT

ΔT=Pt/mc

Doubling energy transfer rate will double the temperature rise. Halving the mass will also double the temperature rise. The change in temperature will be 4 times larger than the initial case, which is 40oC. This

gives the final temperature as 60oC.

Explanation​:
In an ideal gas system, it is assumed that molecules have negligible size and that there are no intermolecular forces. System A most resembles an ideal gas because it satisfies these criteria.

Whilst Systems B and C both contain molecules of significant size with strong intermolecular forces, System B is most likely to exhibit non-ideal gas characteristics due to the relatively high gas pressure, which corresponds to greater proximity between the molecules: a decreased intermolecular distance yields increased intermolecular forces, as well as enhancing the influence of non-negligible molecular size (the total molecular volume constitutes a greater percentage of the container volume).

Explanation​:

Once the switch is closed, the heating element in the circuit on the left  increases in temperature.

This increase affects the thermistor by decreasing its resistance. As a result the current in the circuit on the right increases, causing the lamp's brightness to increase.