Answer:

Explanation:
Using the expression shown below as:

Where,
is the number of vacancies
N is the number of defective sites
k is Boltzmann's constant = 
is the activation energy
T is the temperature
Given that:

N = 10 moles
1 mole = 
So,
N = 
Temperature = 425°C
The conversion of T( °C) to T(K) is shown below:
T(K) = T( °C) + 273.15
So,
T = (425 + 273.15) K = 698.15 K
T = 698.15 K
Applying the values as:

![ln[\frac {2.3}{6.023}\times 10^{-11}]=-\frac {Q_v}{1.38\times 10^{-23}\times 698.15}](https://tex.z-dn.net/?f=ln%5B%5Cfrac%20%7B2.3%7D%7B6.023%7D%5Ctimes%2010%5E%7B-11%7D%5D%3D-%5Cfrac%20%7BQ_v%7D%7B1.38%5Ctimes%2010%5E%7B-23%7D%5Ctimes%20698.15%7D)

Answer: 
Explanation:
Given
Discharge is 
Diameter of pipe 
Distance between two ends of pipe 
friction factor 
Average velocity is given by

Pressure difference is given by

Answer:
Opened Push-button Switch (i.e. a PTM Switch)
Explanation:
Tha's just another symbol for a switch, but this one specifies that the switch is a push-button type of switch.
Since it's not touching and completing the line, the state of the switch is initially open.