Use the following letters to indicate what the instrument measures (letters may be used more than once): w=wind,m=moisture, p=pressure, t=temperature

The correct answer is P= Pressure

Explanation:

Pressure refers to the force exerted over a body, this force is usually measured using the formula F (Force) / A (Area). In the case of the barometer, this instrument's purpose is to measure the air pressure or the force the atmosphere exerts over elements. For doing this, the barometer uses units such as atm (standard atmosphere pressure unit) or Pascal (Newton /square meter). Additionally, the pressure detected by the barometer changes with altitude, temperature, and climate factors. According to this, the letter that should be used for a barometer is "P" as this instrument only measures pressure.

C).

Explanation:

As we know that capacitance of a given capacitor is

now we know that energy stored in the capacitor plates

here if all the dimensions of the capacitor plate is doubled

then in that case

here area becomes 4 times on doubling the radius and the distance between the plates also doubles

So new capacitance is now

so capacitance is doubled

now the final energy stored between the plates of capacitor is given as

so the final energy is