QCM : Fundamentals of Physics and Earth Systems — 20 questions

Explication

For sound waves, shorter wavelength corresponds to higher pitch. Pitch is related to the frequency and wavelength of the wave, not to loudness or speed here.

Explication

Wavelength is the distance between repeating points on a wave, measured along the direction of travel. The maximum height is amplitude, and the number per second is frequency.

Explication

Light brightness is associated with amplitude, so a bigger amplitude means brighter light. Wavelength is more directly linked to color and refraction behavior.

Explication

A prism separates white light because different wavelengths refract by different amounts. This changes the direction of each color differently as it passes through the material.

Explication

Radio waves have the longest wavelengths in the electromagnetic spectrum. The spectrum is ordered by wavelength and frequency.

Explication

Electromagnetic radiation can travel through space and does not require particles traveling through a medium. This is why it can carry energy and information through a vacuum.

Explication

Kinetic energy increases with both mass and the square of speed, so a higher top speed raises kinetic energy. The formula is Ek = 1/2 mv^2.

Explication

Water’s gravitational potential energy is used to spin turbines, and that motion is then converted into electrical energy. This is the key transfer in hydroelectric power generation.

Explication

A testable question changes a measurable factor and observes a measurable outcome, such as magnet count and nails picked up. The other choices are not measurable investigations.

Explication

The force involved is electrostatic force, which comes from attraction or repulsion due to electric charge. Rubbing the PVC pipe increases charge buildup, strengthening the pull.

Explication

Resistance describes how strongly a component opposes current flow. It is not the same as voltage, charge storage, or light output.

Explication

Using Ohm’s law, the total resistance is 6 ohms, so current equals 12 ÷ 6 = 2 A. This matches the series-circuit calculation given.

Explication

The motor works because the magnet’s field interacts with the coil’s field, producing rotation. The magnet is not mainly acting as an energy store or heater.

Explication

This question changes one measurable factor and observes a measurable result, which makes it testable. The other options do not focus on a relevant factor for electromagnet strength.

Explication

The correct order is evaporation, condensation, precipitation, then runoff. This is the continuous movement of water through the system.

Explication

Flowing lava is part of the solid Earth, so it belongs to the geosphere. By contrast, a lifeless polluted river would belong to the hydrosphere.

Explication

Photosynthesis uses light energy to form glucose and oxygen from carbon dioxide and water. The other options describe respiration or unrelated processes.

Explication

Respiration requires oxygen and releases carbon dioxide, which is the reverse of photosynthesis for those gases. It also releases energy from glucose.

Explication

A stated advantage is the possibility of sharper vision than a human eye in the future. The other options describe limitations of older devices or incorrect claims.

Explication

A nanowire is defined as a very small wire with a diameter around 10^-9 m. It is not a lens, a current-carrying household wire, or a chemical process.