The cosmological constant is associated with: A. Gravity weakening B. Dark energy C. Dark matter D. Nuclear force Explanation: Cosmological constant models accelerated expansion.
In plasma physics, Debye length represents: A. Particle velocity B. Screening distance of electric fields C. Temperature gradient D. Magnetic field strength Explanation: Debye length defines electrostatic screening scale.
Which symmetry is broken in superconductivity? A. Translational B. Gauge symmetry C. Rotational D. Time symmetry Explanation: Superconductivity involves spontaneous gauge symmetry breaking.
The Dirac equation predicts existence of: A. Neutrons B. Positrons C. Photons D. Quarks Explanation: Dirac’s relativistic equation led to prediction of antimatter.
In quantum mechanics, expectation value of an observable corresponds to: A. Most probable value B. Average measurement over many identical systems C. Minimum energy D. Maximum probability Explanation: Expectation value is statistical mean of repeated measurements.
Which energy source is fossil fuel? A. Wind B. Solar C. Coal D. Hydro Explanation: Coal is fossil fuel.
Which instrument measures humidity? A. Hygrometer B. Barometer C. Thermometer D. Voltmeter Explanation: Hygrometer measures humidity.
Which cycle includes evaporation? A. Nitrogen B. Carbon C. Water D. Rock Explanation: Water cycle includes evaporation.
Which process produces offspring? A. Respiration B. Reproduction C. Digestion D. Circulation Explanation: Reproduction creates new individuals.