Answer: 430 nm.
Explanation:
The relation of wavelength and frequency is:
Formula used :
where,
= frequency =
= wavelength = ?
c = speed of light = 
Now put all the given values in this formula, we get

Thus the wavelength (in nm) of the blue light emitted by a mercury lamp is 430 nm.
Answer:
option B
Explanation:
It is given that in the tire the recommended pressure is 35 PSI however the current pressure is only 26 PSI which means that pressure in the tire is less than the recommended so the chances of blowout of the tire gets eliminated hence option A is not correct.
Having pressure less in the tire can lead to the Unstable handling of the vehicle.
so correct answer is option B
For the first one, leaves is matter.
for the second one, ability to react
hope this helps