Physics Fundamentals and Technology Quiz

Albert Einstein received the Nobel Prize in Physics in 1921 specifically for his discovery of the photoelectric effect, not for relativity as commonly believed. His work explained how light can eject electrons from materials and established the quantum nature of light, which was revolutionary in understanding light-matter interactions.

Hans Christian Oersted discovered in 1820 that an electric current flowing through a wire produces a magnetic field around it, causing a nearby compass needle to deflect. This was the first demonstration of the relationship between electricity and magnetism. Faraday later expanded on this with electromagnetic induction, while Volta worked on batteries and Henry on self-induction.

To answer this question, the user needs to know what humidity is and how it is measured. Humidity refers to the amount of moisture or water vapor in the air. It is measured using an instrument called a hygrometer.

Option A, Barometer, is not the correct answer because a barometer is used to measure atmospheric pressure, not humidity.

Option B, Thermometer, is not the correct answer because a thermometer is used to measure temperature, not humidity.

Option C, Hygrometer, is the correct answer because a hygrometer is specifically designed to measure humidity. It works by measuring the amount of moisture in the air and expressing it as a percentage of the maximum amount of moisture that the air can hold at a given temperature.

Option D, Hydrometer, is not the correct answer because a hydrometer is used to measure the density of a liquid or the specific gravity of a substance, not humidity.

Therefore, the answer is: C. Hygrometer.

Edwin Hubble provided the first observational evidence for the Big Bang theory in 1929 by discovering that galaxies are moving away from each other and that more distant galaxies recede faster (Hubble's Law). This expansion of the universe suggested it began from a single point. While others developed theoretical aspects, Hubble's astronomical observations were the foundational evidence.

-40° is the temperature where Fahrenheit and Celsius scales intersect. This can be derived from F = (9/5)C + 32. Setting F = C gives -40° as the solution. At 0°, F = 32°. At 40°C, F = 104°, and at 100°C, F = 212°, so none of these are equal.

The period of a simple pendulum depends only on its length (T = 2π√(L/g)) and is independent of mass. Changing the pendulum bob's mass doesn't affect the period, so the clock continues to keep correct time. The pendulum's timekeeping is based on length and gravity, not mass.

A Thyristor can be used to control the speed of a DC motor. Thyristors are semiconductor devices that allow precise control of power flow through variable switching, making them ideal for DC motor speed regulation through voltage control. Thermistors are temperature sensors, Thyratrons are gas-filled tubes, and Transistors alone don't provide the power control needed.

X-rays comprise electromagnetic radiations. X-rays are a form of high-energy electromagnetic radiation with shorter wavelengths than visible light. They are not composed of particles like protons, electrons, or neutrons - they are transverse waves in the electromagnetic spectrum.

The force that causes a spring to return to its normal length is called the restoring force. Restoring force is the force that brings a spring back to its equilibrium position after being stretched or compressed. It follows Hooke's Law (F = -kx) where the force is directly proportional to displacement and acts in the opposite direction. Potential force is not a standard term, gravitational force acts on masses, and spring force is ambiguous.

Electric current will not flow if both bodies have the same potential. Current flows due to potential difference (voltage) between two points. When potentials are equal, there is no driving force for electron flow. Same capacity refers to charge storage, same temperature is irrelevant, and current doesn't always flow - it requires potential difference.

Superconductors are materials which lose all electrical resistance when cooled below a certain temperature (critical temperature). Below this transition point, they exhibit zero electrical resistance and can conduct electricity without any energy loss. This is the defining property of superconductors. They do not become non-conductors, resistance doesn't become infinite, and the term 'extra widths' is meaningless in this context.

Watt-hour measures energy consumed or produced over time. It is calculated by multiplying power (in watts) by time (in hours), making it a unit of energy, not power or instantaneous quantities.

Subrahmanyan Chandrasekhar's work on stellar evolution led to the Chandrasekhar limit, which states that stars above a certain mass must collapse into black holes. This fundamental contribution established him as the discoverer of black hole theory.

Ferrites are ceramic materials that exhibit magnetic properties while having very high electrical resistance. This combination makes them ideal for applications like EMI suppression cores where you want magnetism but minimal eddy current losses.

Kinetic energy is related to linear momentum by the formula KE = p^2 / (2m), where p is momentum and m is mass. If the momentum p is doubled (2p), the kinetic energy becomes (2p)^2 / (2m) = 4 * (p^2 / (2m)), meaning it increases by a factor of four.

Sound actually travels FASTER in humid air because water vapor is less dense than dry air (the molecular weight of H₂O is 18 vs N₂=28, O₂=32). Lower density means faster sound propagation, making statement C the incorrect one.

The rate of change of momentum is force (F = dp/dt), and force is a vector quantity having both magnitude and direction. Kinetic energy, pressure, and density are all scalar quantities with only magnitude, no direction.

Tesla (T) is the SI unit of magnetic flux density, defined as one weber per square meter (Wb/m²). Gauss is a CGS unit, Oersted measures magnetic field strength, and Weber measures magnetic flux.