1. Fill in the blanks
a. Substances which produce large amount of heat on burning are called Fuel.
b. Very low temperature reduce the rate of the growth of bacteria
c. Degree of hotness of a body is called its temperature.
d. Hotness and coldness are comparative term, not absolute.
e. Change of the state is caused by heating or cooling a substance.
f. First stem engine invented by James watt based on the principal of Transformation of energy.
2. What type of energy change takes place in:
a. Thermal power Station: heat energy ®Electrical Energy
b. Nuclear power station: Nuclear energy ® Heat energy ® Electrical Energy
Check point-02 [Formative Assessments]
Fill in the blanks
a. Sir Thomas Clifford Albutt in 1866 invented Clinical thermometer.
b. Thermometer is used to measure temperature.
c. The most commonly use scale to measure temperature is the Celsius scale
d. In the Celsius scale freezing point of water is 00 C and boiling point is 1000C
e. Lab thermometer can measure temperature safely from 00 C to 1000C.
f. The average body temperature is 370C or (98.40C)
g. The highest reading on clinical thermometer is 420C.
h. An object expands on heating and contracts on cooling.
i. The heat can cause change of state in object.
State True and False:
a. A clinical temperature measure temperature up to 1200C [F]
b. A laboratory thermometer has kink in its capillary [F]
c. The degree of hotness cannot be estimated by touching and feeling [T]
d. Disposing of broken thermometer is common trash is harmful to environment [T]
15. Q. How is life of bacteria affected by heat?
Answer: Bacteria cannot grow and multiply at high temperature.
16. Q. State precautions taken while using clinical thermometer?
Answer: We should take following precautions while while using clinical thermometer:-
i)It should be washed before and after using with an antiseptic solution.
ii) We should check or ensures that the mercury level should be 35 degree Celsius before using it.
iii)The reading should be taken while keeping the level of mercury along the line of sight.
iv)W e should not hold the thermometer by its bulb while reading it.
v) We should handle the thermometer with care, as it is breakable.
17. Q. State precautions taken while using Laboratory thermometer?
Answer: precautions taken while using Laboratory thermometer are
a. Bulb of Laboratory thermometer must be in contact of object properly.
b. Reading should be taken without removing from its position.
c. Eyes should be at the vertical level
d. Do not used to measure temperature below - 100C and above 1100C.
18. Q. Why are bottle containing liquid left with some space at the top?
Answer: Bottle containing liquid is left with some space at the top to provide space for expansion of liquid on heating.
19. Q. Why are huge bridge provided with flexible joint?
Answer: flexible joint in huge bridge allow expansion in summer and protect from bending.
20. Define Heat and Energy and temperature.
Answer: According to Rumford and James Prescott, Heat is a form of energy that is known as Thermal Energy. Energy in a substance is due to movement of its molecules.
Energy is capacity to do work. Energy is neither created nor destroyed it can only transformed [changed] one form to another.
Temperature is a measure of the degree of hotness and coldness of an object. S.I unit of Temperature is Kelvin. Other Units are degree Celsius and degree Fahrenheit
Q. (iv) Why digital thermometers are used these days
Ans.: Mercury is a poisonous metal if a thermometer breaks in mouth. . To overcome this, digital thermometers are used these days.