What is the collector current when the base resistor is open?

Will a transistor act as a closed switch by defining the requisite magnitude of saturation level with an equivalent amount of

Number of Pi bonds in phenyl benzoate are ‘X’. Number of lone pairs in phenyl benzoate are ‘Y’ .Correct relation is

For a given gas at same temperature

f1 = fraction of molecules having most probable velocity f2 = fraction of molecules having most probable velocity f3 = fraction of molecules having most probable velocity Then the correct relation between them is

Assertion (A) : Helium obeys gas laws at all temperatures and pressures
Reason (R) : For Helium compressibility factor (Z) < 1 at all temperature and pressures