For a normal eye,the cornea of the eye provides a converging power of $40 \ D$ and the least converging power of the eye lens behind the cornea is $20 \ D$. Using this information,the distance between the retina and the cornea-eye lens can be estimated to be ......... $cm$.

$A$ $U$-tube has a left limb with a cross-sectional area that is one-quarter of the right limb. The tube contains mercury (density $13.6 \ g/cm^3$). The level of mercury in the narrow left limb is at a distance of $36 \ cm$ from the upper end of the tube. What will be the rise in the level of mercury in the right limb if the left limb is filled to the top with water (in $cm$)? (Density of water = $1 \ g/cm^3$)

The overall goal of glycolysis,Krebs' cycle,and the electron transport system is the formation of

Which one of the following is the first step in taxonomy?

Which of the following is an incorrect statement?

$A$ piece of semiconductor is connected in series in an electric circuit. On increasing the temperature,the current in the circuit will