The phrase "varying strength" is correct and usable in written English.
You can use this phrase to describe a situation in which something changes in intensity or power. For example, "The wind blew with varying strength throughout the day."
The methodology of the studies enclosed varied markedly, thus resulting in evidence of varying strength.
Forty-one other states have anti-bullying laws of varying strength.
Today, the extract of black cohosh's roots and rhizome is sold in capsules or tablets of varying strength and dispensed in European pharmacies as a drug.
"The print, with a typed caption, was inserted into a photo transmission device, which would translate various shades of gray to an audio tone of varying strength.
Before now, only medical workers could use defibrillators, which administer shocks of varying strength to a heart that has stopped beating normally.
The wind patterns caused by the varying strength of the NAO are a key cause of either drought or surplus precipitation in Europe.
With electrical charges of varying strength, the filter separates and extracts different rare earth elements used in such advanced electronics as smartphones and plasma screen TVs.
Murray explored a theory of personality in which the interplay of 20 psychogenic needs of varying strength produced distinct personality types.
Its varying strength at the Earth's surface as the Moon orbits might, he thinks, also affect a bird's putative gravitational sense.
To simulate a perforated completion, cylindrical sand samples with varying strength and porosity were prepared.
Other effects, such as diet, exercise, and the varying strength of the effects of particular genetic sequences, can all play a role in whether or not a genetic predisposition leads to an actual malady.
