Скачать или смотреть Numerical Problems | Physics 9th | Chapter 8 | Thermal Properties of Matter | KPK Textbook Board

Q. Choose the best possible option.
The S.I unit of heat is
(a) J (b) kg (c) K^(-1) (d) K
The S.I unit of temperature is
(a) ℃ (b) ℉ (c) J (d) K
The Fahrenheit and Celsius scale reading of temperature coincide at
(a) 0° (b) -460° (c) -273° (d) -40°
310K in centigrade scale is
(a) 37℃ (b) 310℃ (c) 63℃ (d) 273℃
When water at 0℃ is heated, it contacts till temperature reaches
(a) 1℃ (b) 4℃ (c) 100℃ (d) 100K
The S.I unit of specific heat is
(a) 〖JK〗^(-1) (b) JK^(-1) 〖kg〗^(-1) (c) J〖kg〗^(-1) (d) JKkg
The relation between coefficient of linear and volume expansion is;
(a) α=3γ (b) γ=3α (c) γ=α/2 (d) γ=6α
The S.I unit of latent heat is
(a) 〖JK〗^(-1) (b) 〖Jkg〗^(-1) (c) JK〖kg〗^(-1) (d) JKkg
How much heat is required to melt of 1kg of Zink at its boiling temperature 240℃ with latent heat of 113×〖10〗^3 J〖kg〗^(-1)
(a) 113×〖10〗^3 J (b) 1.13×〖10〗^3 J (c) 2.4×〖10〗^5 J (d) 2.71×〖10〗^7 J
The amount of heat required to raise the temperature of 1kg of water by 1K is
(a) 1J (b) 400J (c) 310J (d) 4190J
Q. Give a short response to the following questions
Ordinary electric fan increases the kinetic energy of the air molecules caused by the fan blades pushing them means the air temperature increases slightly rather than cool the air? Why use it?
Why are small gaps left behind the girders mounted in walls?
Why you should not put a closed glass jar into a campfire. What could happen if you tossed an empty glass jar, with the lid on tight, into a fire?
Explain why it is advisable to add water to an overheated automobile engine only slowly, and only with the engine running.
Explain why burns caused by steam at 100℃ on the skin are often more severe than burns caused by water at 100℃.
Explain why cities like Karachi situated by the ocean tend to have less extreme temperature than inland cities at the same latitude.
An iron rim which is fixed around a wooden wheel is heated before its fixture. Explain why?
Why is ice at 0℃ a better coolant of soft drinks then water at 0℃?
Why we feel cool after perspiration?
Q. Solve the following numerical questions.
Perform the temperature conversions (a) Temperature difference in the body. The surface temperature of the body is normally about 7℃ lower than the internal temperature. Express this temperature difference in kelvins and in Fahrenheit degrees. (b) Blood storage. Blood storage at 4.0℃ lasts safely for about 3 weeks, whereas blood stored at -160℃ lasts for 5 years. Express both temperatures on the Fahrenheit and Kelvin scales.
Consider a metre-stick composed of platinum (the coefficient of linear expansion for platinum is α=8.8×〖10〗^(-6) K^(-1)).By what amount does the length of this metre-stick change if the temperature increases by 1.0K?
A railway line made of iron is 1200km long and is laid at 25℃. By how much will it contract in winter when the temperature falls to 15℃? By how much will it expand when the temperature rises to 40℃ in summer? (the coefficient of linear expansion for iron is α=12×〖10〗^(-6) K^(-1)).
The volume of a brass ball is 800〖cm〗^3 at 20℃. Find out the new volume of the ball if the temperature is raised to 52℃. The coefficient of volumetric expansion of brass is 57×〖10〗^6 K^(-1).
What is the specific heat of a metal substance if 135kJ of heat is needed to raise 4.1kg of the metal from 18.0℃ to 37.2℃?
How much heat is needed to melt 23.50kg of silver that is initially at 25℃? (Specific heat of silver is c=230J〖kg〗^(-1) K^(-1). Latent heat of fusion for silver is L_f=8.82×〖10〗^4).