14. Why is the bulb of the frermometer made of this glass?
15. Convert the great perzturs to degs Celsius 150degzef and 43 degzef
16. Conven the given temperature to degree fahrenheit 150degree C and 32 degree
17. Define the following a) Temperature b) conduction c) convection ) Radiation e) thermal energy.
18. write the relation between the Celsius and fahrenheit scale?
19. What is a heat insulator?
Answers
Answer:
14.Clinical thermometers are made up of glass because glass has very low co efficient of thermal expansion it is a bad conductor of heat and it is transparent.
15 .Fahrenheit is a temperature measuring scale and unit, named after German physicist Daniel Gabriel Fahrenheit, who created this scale in 1724.
16. Hence to convert it to f, to calculate the corresponding fahrenheit of 150 celsius, just multiplying 150 into 9/5 then add final value to 32 is equal to 302 f. How to Calculate 150 c to f? fahrenheit = (150°C × 9/5) + 32.
17 Conduction transfers heat via direct molecular collision. An area of greater kinetic energy will transfer thermal energy to an area with lower kinetic energy. Higher-speed particles will collide with slower speed particles. The slower-speed particles will increase in kinetic energy as a result. Conduction is the most common form of heat transfer and occurs via physical contact. Examples would be to place hand against a window or to place metal into an open flame.
When a fluid, such as air or a liquid, is heated and then travels away from the source, it carries the thermal energy along. This type of heat transfer is called convection. The fluid above a hot surface expands, becomes less dense, and rises. At the molecular level, the molecules expand upon introduction of thermal energy. As temperature of the given fluid mass increases, the volume of the fluid must increase by same factor. This effect on the fluid causes displacement. As the immediate hot air rises, it pushes denser, colder air down. Example would be the flow of wind.
Thermal radiation generates from the emission of electromagnetic waves. These waves carry the energy away from the emitting object. Radiation occurs through a vacuum or any transparent medium (either solid or fluid). Thermal radiation is the direct result of random movements of atoms and molecules in matter. Movement of the charged protons and electrons results in the emission of electromagnetic radiation. All materials radiate thermal energy based on their temperature. The hotter an object, the more it will radiate. The sun is a clear example of heat radiation that transfers heat across the solar system. At normal room temperatures, objects radiate as infrared waves.
18 .The formula to convert from Celsius to Fahrenheit is F= (9/5 x C) + 32.
19 .Thermal insulation is the reduction of heat transfer between objects in thermal contact or in range of radiative influence. Thermal insulation can be achieved with specially engineered methods or processes, as well as with suitable object shapes and materials