The area (in square units) of the circle which touches the lines $4x + 3y = 15$ and $4x + 3y = 5$ is

Two rigid boxes containing different ideal gases are placed on a table. Box $A$ contains one mole of nitrogen at temperature $T_0$,while box $B$ contains one mole of helium at temperature $(7/3) T_0$. The boxes are then put into thermal contact with each other,and heat flows between them until the gases reach a common final temperature (Ignore the heat capacity of boxes). Then,the final temperature of gases,$T_f$,in terms of $T_0$ is

Human urine is usually acidic because:

If the angular momentum of an electron is $\overrightarrow{J}$,then the magnitude of the magnetic moment will be

Which is the most important center for lymph formation?

This is the only type of pollination which during pollination brings genetically different types of pollen grains to the stigma.