Practice MCQ Questions and answers on Physics-GK

Adding salt to the water increases the density of the solution because the salt increases the mass without changing the volume very much. When enough salt is added to the water, the saltwater solution's density becomes higher than the egg's, so the egg will then float.

Steam produces more severe burns than boiling water even though both are at 100^oC because steam contains more heat, in the form of latent heat, than boiling water.

Heat capacity (usually denoted by a capital C, often with subscripts), or thermal capacity, is the measurable physical quantity that characterizes the amount of heat required to change a substance’s temperature by a given amount. In the International System of Units (SI), heat capacity is expressed in units of joule(s) (J) per Kelvin (K). Among iron piece, water, gold piece and benzene; water has the maximum heat capacity i.e. 4.1813 j/k.

Steam produces more severe burns than boiling water even though both are at 100^oC because steam contains more heat, in the form of latent heat, than boiling water.

When air is cooled and water vapour condenses to form water liquid, energy is released as water particles 'give up' some of their energy in order to slow down and move closer together again. The same is true when liquid water freezes to become ice. This energy is also called latent heat.

Among all the four water has the highest specific heat.

The specific heat of water is higher than all other common substances. Hence, water is used for heating purposes (as in hot water bottles) and for cooling purposes (as in radiators of cars). Off all the liquids, mercury has the lowest specific heat due to which it is used as a thermometric liquid .

Water is used as a coolant in automobiles radiators because it has high specific heat capacity. So, it absorbs a large amount of heat for a degree rise in temperature.

It takes 80 calories to melt 1 gram of ice. If 1 g of ice (at 0 degrees Celsius) is given 80 calories, it will melt and the final temperature of the water will be 0. Freezing water at 0 degrees Celsius: It also takes 80 calories to freeze 1 gram of water.

Water pipes burst because the water inside them expands is it gets close to freezing, and this causes an increase in pressure inside the pipe.