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​:
I.  Chemical energy in fossil fuel is transformed into thermal energy by burning and thermal energy is used to move (kinetic energy) steam that rotates the turbine and generator (also kinetic energy). Finally, electric energy is produced in generators.

II.  The kinetic energy of wind rotates the blades (kinetic energy) and rotates the generator. Finally, electric energy is produced in a generators.

III.  The gravitational potential energy of water behind a dam converts into kinetic energy as water falls down and rotates the turbine and generator. Finally, electric energy is produced in generators.

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​:
Due to the fixed volume, the separation between the gas molecules decreases. According to the ideal gas law, the pressure of the gas will increase and so does the collision frequency. The mass of the container will also be greater with the addition of more gas in the container. The only constant quantity is the average size of the molecules. It is dependent on molecular structure only. Therefore the answer is C.

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​:

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.

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

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​:

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​:

60$J$ per second gives power, P=60W

$A$ therefore the answer is A.

Explanation​:

The kinetic model of ideal gases assumes that intermolecular forces (and therefore intermolecular potential energy) are negligible, and that the mean kinetic energy of molecules is directly proportional to gas temperature; hence, Properties I and II stay constant during the expansion. Conversely, Property III changes because gas pressure decreases during the expansion, and pressure scales with the frequency of molecular collisions with the walls of the piston.

Explanation​:
Uranium is a non-renewable source of energy whereas wind is renewable.

Explanation​:

The temperature of the solid is 373 $K$ (100 + 273) after the reaction takes place, so a temperature change of $(373-50)=323K$ is required to achieve the target temperature.

The energy $E$ needed for this change is related to the temperature change $\Delta T$ by the expression

E=mcΔT=323mc

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​:

• A. All electrical components are resistors to some extent. Even the best conductors will take up some amount of energy as electricity flows through them.
• B. While all materials are conducting given the appropriate voltage, at voltages as low as those shown on the graph, no current would flow if the material was not a good conductor of electricity.
• C. According to the graph, the ratio $V$/$I$ is not constant. By definition, that indicates a non-ohmic resistor. C is the correct answer.
• D. The voltage-current graph of an ohmic resistor is a straight line whose gradient represents a constant resistance.

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​:
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​:

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​.