(x-x)?
in the formula used to calculate standard deviation, v
(n-1)
, what does x stand for
c(x-x?
in the formula
)
which is used to calculate standard deviation, x stands for

there are more correct choices on the list than incorrect ones.

the inverse square law applies to

-- the intensity of sound from a small source

-- the gravitational force

-- the intensity of light from a small source

-- the electric force   from a point charge or a small charge.

it doesn't apply to the magnetic force.

answer : to provide heat.

explanation :

infrared waves are the waves having wavelength 700 nm to 1 mm.

the most common use of infrared waves is "to provide heat" i.e. in heat-sensitive thermal imaging cameras. it is a invisible wave. it can only sensed by a sensation of warmth.

for example :

when an object is hot, it will emit energy in the form of infrared waves.

so, correct option is (b)

earthquakes are normally associated when two tectonic plates move away from each other causing a rift in the plate and you get an earthquake.

d. mass per unit volume