John Walker invented
The instrument, used for recording tremors of earth, is known as
Which of the following is a gas?
The material used for bleaching paper pulp is
Nitrogen is prepared in the laboratory by heating
Which one of the following represents a chemical change?
The time interval between two beats of a normal human heart is
A thermostat is
(a) An instrument by which the accuracy of thermometers is determined
(b) A modern type of thermos flask which works on the principle of equipartition of heat energy
(c) A device used to maintain a constant temperature of a water bath or an oven
(d) A device that varies the temperature of a bath
Submitted By: Syed Bilawal Shah (Sain) …