The splitting of white light into its constituent colors by a prism is due to MCQ with Answer and Explanation

Explanation:
Echo is the reflection of sound waves from a rigid surface, returning to the listener after a time delay. For distinct echo, minimum distance to reflector is about 17 m (so time delay > 0.1 s, persistence of hearing). Refraction bends sound in media with varying density; interference combines waves; diffraction bends around obstacles. Memory tip: 'Echo = sound reflection like light in mirror'. This application-based question links wave properties to daily-life phenomena, frequently tested in competitive exams to assess conceptual clarity beyond definitions. Always distinguish echo from reverberation (multiple reflections).

Explanation:
Power = work done per unit time = kinetic energy imparted per second. KE per bullet = ½mv² = ½×0.01×(600)² = 1800 J. Bullets per second = 60/60 = 1. Thus power = 1800 J/s = 1800 W. Note: Mass conversion: 10 g = 0.01 kg. This problem combines kinetic energy formula with power definition. Exam tip: Always convert to SI units first (grams to kg, minutes to seconds). Such numerical problems test multi-step calculation skills and unit conversion proficiency essential for competitive examinations.

Explanation:
According to Gauss's Law in electrostatics, all excess charge on a conducting body resides entirely on its outer surface. Since there is no net charge enclosed within the hollow interior, the electric flux and consequently the electric field everywhere inside the hollow conducting sphere is exactly zero.