Question Detail Solar cell converts Sound energy into electrical energyElectrical energy into mechanical energySolar energy into electrical energyElectrical energy into light energy Answer: Option C Similar Questions : 1. What is unit of Viscosity ? coulombnewton second per square meterwatt per meter per degree celciusjoule per kilogram per Kelvin Answer: Option BExplanation:coulomb is unit of Electric Charge, watt per meter per degree celcius is unit of Thermal Conductivity, joule per kilogram per Kelvin is unit of Specific Heat capacity. 2. Which instrument is used to measure heat radiation ? RadarSalinometerRefractometerRadio micrometer Answer: Option DExplanation:Radar - is used to detect the direction and speed of an object by means of radiowaves, Salinometer - is used to determine salinity of solutions, Refractometer - is used to measure refractive indices. 3. David Hughes invented Machine GunMicrophoneMicroscopeMotorcycle Answer: Option BExplanation:David Hughes of USA invented Microphone in 1878, Machine Gun was invented by Richard Gatling of USA in 1861, Microscope was invented by Z. Jansen of Netherlands in 1590, Motorcycle was invented by Edward Butler of England in 1884. 4. Marie and Pierre Curie invented RadioRadiumRadarRefrigerator Answer: Option BExplanation:Marie and Pierre Curie of France invented Radium in 1898, Radio was invented by G. Marconi of England in 1901, Radar was invented by Dr. A.H. Taylor and L.C. Young of USA in 1922, Refrigerator was invented by J. Harrison and A. Catlin of Britain in 1834. 5. Force of attraction between the molecules of different substances is called Surface tensionCohensive forceAdhesive forceNone of above Answer: Option CExplanation:Cohensive force - Force of attraction between the molecules of same substance is called Cohensive force. Read more from - Physics Questions Answers