Science [1 Mark Questions]

The ratio of increase in length of the body per degree rise in temperature to its unit length is called as the coefficient of linear expansion. The SI unit of Coefficient of Linear expansion is K-1.

One kilocalorie is defined as the amount of heat energy required to rise the temperature of 1 kilogram of water through 1°C.

If the lorry is moving with uniform speed the speed of cooking gas molecules will also be uniform and the collisions will be least or loss of K.E will be least in turn increase in temperature will be less. If the lorry is not moving with uniform the cylinders and molecules collide more and more and their temperature may increase and can cause the fire in gas.

Thermal energy is a form of energy which is transferred between any two bodies due to the difference in their temperatures. Thermal energy is also known as ‘heat energy’ or simply ‘heat’.

Either due to temperature variation in summer and winter or due to frictional force between the wheel of train and rail, when the temperature increases the length of rail will increase and may bend in summer and the train may get derailed.

When heat energy is supplied to a substance the E of molecule or atoms increases so the average distance between then increases. So the volume of matter (solid, liquid, gas) increases.

Two or more physical systems or bodies are said to be in thermal equilibrium if there is no net flow of thermal energy between the systems.

All solid bodies do not expand on heating, semiconductor and camphor contracts on heating.

The temperature of a body can never be negative on kelvin. Because the lowest temperature on the Kelvin scale is 0 kelvin.

The commonly used units of temperature are Kelvin, degree Celsius (°C) and degree Fahrenheit (°F).

It is the temperature at which the three phases of water and gas of water are equally stable.