A piece of ice is floating in a glass of water. When ice melts, water level MCQ with Answer and Explanation

Explanation:
1/R_eq = 1/3 + 1/3 + 1/3 = 1 ⇒ R_eq = 1Ω. For n equal resistors in parallel: R_eq = R/n. Memory tip: 'Parallel: reciprocal sum; result < smallest resistor'. Basic circuit calculation frequently tested in competitive exams to verify parallel combination formula.

Explanation:
SONAR uses ultrasonic waves (>20 kHz) for better directionality, resolution, and reduced absorption in water. Audible sound (20Hz-20kHz) diffracts more; infrasonic (

Explanation:
For constant pressure (isobaric) process, work done by gas W = PΔV, where ΔV is change in volume. This derives from mechanical work W = F·d and pressure P = F/A, so F = PA, and dV = A·d, thus W = P·dV. Option D Δ(PV) applies to other contexts like enthalpy. Memory tip: 'Isobaric work = P times volume change'. This fundamental thermodynamics result is frequently used in first law applications. Competitive exams often combine this with ideal gas law for numerical problems; always verify process constraints (constant P here).