$P_4O_{10}$ has short and long $P-O$ bonds. The number of short $P=O$ bonds in this compound is

What is the shape of an ookinete?

Calculate the surface temperature of the planet,if the energy radiated by unit area in unit time is $5.67 \times 10^4 \, W$. (Assume the planet is a black body).

The angle of a prism is $A.$ One of its refracting surfaces is silvered. Light rays falling at an angle of incidence $2A$ on the first surface return back through the same path after suffering reflection at the silvered surface. The refractive index $\mu$ of the prism is

Two identical piano wires,kept under the same tension $T$,have a fundamental frequency of $600\, Hz$. The fractional increase in the tension of one of the wires which will lead to the occurrence of $6\, beats/s$ when both the wires oscillate together is:

Carbon,silicon,and germanium have four valence electrons each. These are characterized by valence and conduction bands separated by energy band gaps equal to $(E_{g})_{C}$,$(E_{g})_{Si}$,and $(E_{g})_{Ge}$ respectively. Which of the following statements is true?