Introduction to Acid and Base — Science STD 8 — Question

Which one of the following four metals would be displaced from the solution of its salt by the other three metals?

Electric door bell employs:

When we press the bulb of a dropper with its nozzle kept in water air in the dropper is seen to escape in the form of bubbles. Once we release the pressure on the bulb, water gets filled in the dropper. The rise of water in the dropper is due to:

What happens when we become sick?

Which of the following scientists gave the idea of the existence of gravitational force?

A brick is kept in three different ways on a table as shown in given figure. The pressure exerted by the brick on the table will be:

Coils of heating devices are made up of:

An element measure the potential difference between two points in an electric circuit is:

An element burns in air to form an oxide. The aqueous solution of this oxide turns turmeric paper red. State whether the element is a metal or non-metal. Name one such element.

Which of the following mobile apps can be used to obtain generic medicines?