What is the criteria t select the protection diode for solar cell and give your reason. Forward mode Reverse mode Solution option (b) reverse mode is correct. When the sun shines, than the voltage produced by the panel will be greater than that of the battery, then charging will take place. However, during dark, when no voltage is being produced by the panels, the voltage of the battery would cause a current to flow in the opposite direction through the panels, therefore discharging the battery, if the diode in the circuit is not in the reverse mode in the circuit then discharging of battery takes place so therefore the diode should be in reverse mode in order to protect batteries. Blocking diodes will be of benefit in any system using solar panels to charge a battery..

1. What is the critical F value for a sample of 7 observations in the numerator and 6 in the
denominator? Use a two-tailed test and the 0.1 significance level.(Round your answer to 2
decimal places.)
Solution
Number of observations in numerator = 7
Number of observations in denominator = 6
So, df(numerator) = df1 = 7-1 = 6
df(denominator) =df2 = 6-1 = 5
Value of alpha is given as 0.1
Now check the F value table.
I am putting a link of it here.
http://www.socr.ucla.edu/applets.dir/f_table.html
The critical value is 3.40451