Answer:
Total 3 holes are available for conduction of current at 300K.
Explanation:
In order to develop a semiconductor, two type of impurities can be added as given below:
- N-type Impurities: Pentavalent impurities e.g. Phosphorous, Arsenic are added to have an additional electron in the structure. Thus a pentavalent impurity creates 1 additional electron.
- P-type Impurities: Trivalent impurities e.g. Boron, Aluminium are added to have a positive "hole" in the structure. Thus a trivalent impurity creates 1 hole.
Now for estimation of extra electrons in the impured structure is as

Now for estimation of "holes" in the impured structure is as

Now when the free electrons and "holes" are available in the structure ,the "holes" will be filled by the free electrons therefore

So total 3 "holes" are available for conduction of current at 300K.
In an undeveloped country, the rural areas will often be off the grid, with no access to consistent electricity. For a household living in this situation, <u>wood</u> would most likely be used to heat the home in the winter.
<u>Explanation:</u>
With the help of wood, we can burn it and make fire to heat the house in winter. In the earlier days, wood was used to produce heat and was used for cooking and other purposes.
So when a rural area does not have electricity,stoves would be fired with either biomass fuels, such as wood, branches, twigs or dung, or coal. Also for heating the home, the same would be used. These fuels are collected from the local environment in rural areas and purchased through markets in urban areas. Even now in some countries like India and China use wood or any other biomass fuel for heating and cooking.
Delis cactus is the correct way to write it.
You have to use the specific heat equation.
Q = cmΔT where Q is the energy, c is specific heat, m is mass, and ΔT is change in temp.
So we can substitute our variables into the equation.
30000J = (390g)(3.9J*g/C)ΔT
Solving for ΔT, we get:
30000J/[(390g)*(3.9J*g/C) = ΔT
ΔT = 19.72386588C
I'm assuming the temperature is C, since it was not specified.
Hope this helps!