SONAR (Sound Navigation and Ranging) uses ultrasonic waves (frequency > 20 kHz) because they have high directionality, short wavelength for better resolution, and minimal absorption in water. Radio waves attenuate rapidly in water; infrasonic waves have long wavelengths unsuitable for detection; light doesn't propagate far in water. Memory tip: 'Ultra = beyond human hearing; used in SONAR/ultrasound imaging'. This application question tests knowledge of wave frequency ranges and their practical uses, common in competitive exams linking physics to technology. Always recall frequency thresholds: infrasonic 20kHz.
Explanation:
Potential energy: gravitational (mgh), elastic (½kx²). Kinetic energy due to motion. Total mechanical energy sum conserved in conservative forces.
Explanation:
Archimedes' principle: buoyant force = weight of displaced fluid. Law of floatation: floating body displaces fluid equal to its own weight. Archimedes discovered it. Pascal gave pressure law.
Explanation:
Diamagnetic materials have small negative susceptibility (χ ≈ -10⁻⁵), meaning they weakly repel magnetic fields. Paramagnetic: small positive χ; ferromagnetic: large positive χ. This classification is based on response to external magnetic fields. Memory aid: 'Diamagnetic: repelled by magnets; χ < 0'. This conceptual question tests magnetism fundamentals, crucial for competitive exams. Always link susceptibility sign to material behavior: negative χ ⇒ diamagnetic (weak repulsion), positive ⇒ paramagnetic/ferromagnetic (attraction).
No comments yet. Be the first to start the discussion!