Physics Past Questions

A metallic wire of initial length 10 m is cooled from 50°C to 10°C. Calculate the absolute decrease in the length of the wire. [Linear expansivity $$\alpha = 3 \times 10^{-5}\text{ K}^{-1}$$]

What will happen theoretically to the net pressure exerted by an ideal gas system if its absolute temperature is reduced all the way down to -273.15°C?

A sample of helium gas has a mass of 0.354 g, a volume of 2667 cm?, a temperature of 273°C, and a pressure of 114 cmHg. Calculate its corresponding volume when converted to Standard Temperature and Pressure (STP, where T = 273 K and P = 76 cmHg).

A copper rod of length 5.0 m expands linearly by 1.0 mm when it is heated through a temperature change of 20°C. If a second copper rod of length 2.5 m is heated through a temperature change of 5°C, calculate its linear expansion.

The actual mass of water vapour present in a given volume of air is 0.05 g at 20°C, whereas the mass of water vapour required to completely saturate that exact same volume at 20°C is 0.15 g. Calculate the relative humidity of the air sample.

During a laboratory experiment, a sample of molten naphthalene is allowed to cool down gradually over time while its temperature is monitored. A flat horizontal plateau is observed on its cooling curve at a steady temperature of 80°C. This specific temperature value is known as the:

The temperature gradient across a uniform copper rod of thickness 0.02 m, maintained at two temperature junctions of 20°C and 80°C respectively, is:

Thermal energy is supplied uniformly at a rate of 100 W to a sample of liquid having a mass of $$1.0 \times 10^{-2}\text{ kg}$$ for a duration of 20 seconds. If the temperature of the liquid increases by 5°C, calculate the specific heat capacity of the liquid.

Which formula correctly expresses the relationship between Mechanical Advantage (M.A), Velocity Ratio (V.R), and percentage Efficiency?

A dynamic explosion occurs at an altitude of 312 m directly above the ground. If the ambient air temperature is uniform at -10.00°C, calculate how long it takes for the acoustic sound wave to reach an observer on the ground. [Take velocity of sound at 0°C = 331 m/s]

Convert 45°C to kelvin.

288 kJ is conducted across a 3 m cube with a temperature gradient of 90°C/m in 7200 s. Calculate the thermal conductivity (k).