SUMMATIVE ASSESSMENT 1 FOR CBSE CLASS 9 (GRAVITATION)

Find below a question bank from the chapter GRAVITATION of class 9. Portions up to the syllabus for Summative assessment 1 only is included. The answers are not published herewith. Students are advised to solve the questions and problems and post the q...

The SI & CGS unit of time is same .Why?

Almost in all systems of unit second is the unit of time, most probably because, second is the most convenient one, if we look at the guidelines for selecting a unit. For more details refer to the following links http://www.aticourses.com/international_system_units.htm http://www.french-metrology.com/en/history/history-mesurement.asp http://physics.nist.gov/cuu/Units/history.html http://en.wikipedia.org/wiki/Metric_system http://en.wikipedia.org/wiki/Systems_of_measurement Incoming search terms:cgs unit for timeThe SI & CGS unit of [...]

Differences between mass and charge

Charge is of two types, mass is only of one kind There are two types of forces (attraction and repulsion) between charges, but there is only one kind (attraction) between masses Charge is quantized, but quantization of mass is not established so far Charge has SI unit coulomb, the SI unit of mass is kg … Continue reading Differences between mass and charge