If vectors are arranged as trigonal planar and have equal magnitude, it is an ideal case of zero resultant.
This picture develops a clear understanding.

The answer is A
In the depletion layer, electrons combine with holes producing charge density so that region is depleted of charge carriers but it has charge density .
Conclusion: Neutral but still having non zero charge density .
In mitosis, the prophase is further understood by dividing it into the given sub-stages:
1.Leptotene :
In this stage the nucleus enlarges in size in the chromosome. The chromosomes appear thin, thread-like and single-stranded in this stage. They have swollen or beaded structures along their length and their ends appear converged towards one side of the nucleus called bouquet.
2.Zygotene:
In this stage, the identical chromosomes come together and form bivalent or homologous pairs. Further, ...
1. How many beats can be heard by sounding together two tuning forks of frequencies 250Hz and 256Hz?
Number of beats (n) =f2- f1
= 256 - 250
= 6 beats /sec