Study the following and pick up the correct statements:
I. The peripheral doublets of a flagellum are interconnected by linkers called nexins.
II. The basal granule of flagellum is connected to plasma membrane and nucleus by rootlets.
III. Flagellum in Monas are strichomonate type.
IV. Pantomonemantic flagellum is found in Polytoma.




Which of the following microbes is NOT involved in the preparation of household products?
A. \(\textit{Aspergillus niger}\)
B. \(\textit{Lactobacillus}\)
C. \(\textit{Trichoderma polysporum}\)
D. \(\textit{Saccharomyces cerevisiae}\)
E. \(\textit{Propionibacterium sharmanii}\)
Two concentric thin circular rings of radii 50 cm and 40 cm each, carry a current of 3.5 A in opposite directions. If the two rings are coplanar, the net magnetic field due to the two rings at their centre is: