This question is incomplete, the complete question is;
Calculate the value of ni for gallium arsenide (GaAs) at T = 300 K.
The constant B = 3.56×10¹⁴ (cm⁻³ K^-3/2) and the bandgap voltage E = 1.42eV.
Answer: the value of ni for gallium arsenide (GaAs) is 2.1837 × 10⁶ cm⁻³
Explanation:
Given that;
T = 300k
B = 3.56×10¹⁴ (cm⁻³ K^-3/2)
Eg = 1.42 eV
we know that, the value of Boltzmann constant k = 8.617×10⁻⁵ eV/K
so to find the ni for gallium arsenide;
ni = B×T^(3/2) e^ ( -Eg/2kT)
we substitute
ni = (3.56×10¹⁴)(300^3/2) e^ ( -1.42 / (2× 8.617×10⁻⁵ 300))
ni = (3.56×10¹⁴)(5196.1524)e^-27.4651
ni = (3.56×10¹⁴)(5196.1524)(1.1805×10⁻¹²)
ni = 2.1837 × 10⁶ cm⁻³
Therefore the value of ni for gallium arsenide (GaAs) is 2.1837 × 10⁶ cm⁻³
Answer:
Yield strength, tensile strength decreases with increasing temperature and modulus of elasticity decreases with increasing in temperature.
Explanation:
The modulus of elasticity of a material is theoretically a function of the shape of curve plotted between the potential energy stored in the material as it is loaded versus the inter atomic distance in the material. The temperature distrots the molecular structure of the metal and hence it has an effect on the modulus of elasticity of a material.
Mathematically we can write,
![E(t)=E_o[1-a\frac{T}{T_m}]](https://tex.z-dn.net/?f=E%28t%29%3DE_o%5B1-a%5Cfrac%7BT%7D%7BT_m%7D%5D)
where,
E(t) is the modulus of elasticity at any temperature 'T'
is the modulus of elasticity at absolute zero.
is the mean melting point of the material
Hence we can see that with increasing temperature modulus of elasticity decreases.
In the case of yield strength and the tensile strength as we know that heating causes softening of a material thus we can physically conclude that in general the strength of the material decreases at elevated temperatures.
I have added the answer as a pic due to difficulties pasting the text here.
Answer:
The solution code is written in Python:
- def convertCSV(number_list):
- str_list = []
- for num in number_list:
- str_list.append(str(num))
-
- return ",".join(str_list)
- result = convertCSV([22,33,44])
- print(result)
Explanation:
Firstly, create a function "convertCSV" with one parameter "number_list". (Line 1)
Next, create an empty list and assign it to a new variable <em>str_list</em>. (Line 2)
Use for-loop to iterate through all the number in the <em>number_list</em>.(Line 4). Within the loop, each number is converted to a string using the Python built-in function <em>str() </em>and then use the list append method to add the string version of the number to <em>str_list</em>.
Use Python string<em> join() </em>method to join all the elements in the str_list as a single string. The "," is used as a separator between the elements (Line 7) . At the end return the string as an output.
We can test the function by calling the function and passing [22,33,34] as an argument and we shall see "22,33,44" is printed as an output. (Line 9 - 10)
Answer:
sum2 = 0
counter = 0
lst = [65, 78, 21, 33]
while counter < len(lst):
sum2 = sum2 + lst[counter]
counter += 1
Explanation:
The counter variable is initialized to control the while loop and access the numbers in <em>lst</em>
While there are numbers in the <em>lst</em>, loop through <em>lst</em>
Add the numbers in <em>lst</em> to the sum2
Increment <em>counter</em> by 1 after each iteration
