Option “B” is correct. α -Hydroxy acids, or alpha hydroxy acids (AHAs), are a class of chemical compounds that consist of a carboxylic acid substituted with a hydroxyl group on the adjacent carbon. They may be naturally occurring or synthetic. AHAs are well known for their use in the cosmetics industry. They are often found in products that aid in the reduction of wrinkles, that soften strong, defining lines, and that improve the overall look and feel of the skin.
37.
What is the full form of “VLF”?
a.
b.
c.
d.
Option “B” is correct. Very low frequency or VLF is the designation for radio frequencies (RF) in the range of 3 – 30 kHz, corresponding to wavelengths from 100 to 10 km, respectively. The band is also known as the myriameter band or myriameter wave as the wavelengths range from one to ten myriameters (an obsolete metric unit equal to 10 kilometers).
38.
What is the full form of “VHF”?
a.
b.
c.
d.
Option “B” is correct. Very high frequency (VHF) is the designation for the range of radio frequency electromagnetic waves (radio waves) from 30 to 300 megahertz (MHz), with corresponding wavelengths of ten meters to one meter. Frequencies immediately below VHF are denoted high frequency (HF), and the next higher frequencies are known as ultra high frequency (UHF).
39.
What is the full form of “UHF”?
a.
b.
c.
d.
Option “D” is correct. Ultra high frequency (UHF) is the designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (one decimeter). Radio waves with frequencies above the UHF band fall into the super-high frequency (SHF) or microwave frequency range.
40.
What is the full form of “TB”?
a.
Tuberculosis
b.
c.
d.
Option “A” is correct. Tuberculosis (TB) is a contagious infection that usually attacks your lungs. It can also spread to other parts of your body, like your brain and spine. A type of bacteria called Mycobacterium tuberculosis causes it.
