For the following questions answer them individually
An incident ray strikes a plane mirror at an angle of $$20^\circ$$ with the mirror. The angle between the incident ray and reflected ray is ............
Give an example of a salt which gives an aqueous solution of pH less than 7.
Which of the following_ statements is true?
In which year did Ole Romer measure the speed of light for the first time in the history?
When a glass is rubbed by a silken cloth, the rod acquires