Dobson unit or DU is the measurement unit defining ……..
a) acid rain
b) global warming
c) pollution
d) ozone layer thickness
Explanation: 100 DU indicate that the ozone layer is 1 mm thick
Why people living in equator region have dark skin?
a) to maximize the absorption of vitamin D
b) to protect them from damaging effects of UV rays of the Sun
c) due to heat stroke
d) due to low temperature
CFCs are mainly responsible for……..
a) acid rain
b) ozone layer depletion
c) water pollution
d) air pollution
Explanation: the thinning of the ozone layer present in the upper atmosphere.
CFC gases are produced from……
a) automobile engine
b) refrigeration and air condition
c) burning of charcoal
d) burning of coal
Explanation: Chlorofluorocarbons and hydrochlorofluorocarbons are fully or partly halogenated hydrocarbons that contain carbon, hydrogen, chlorine, and fluorine, produced as volatile derivatives of methane, ethane, and propane.
Why people living near polar region at high latitudes have fair skin?
a) to maximize the absorption of vitamin D
b) to protect them from damaging effects of UV rays of the Sun
c) due to heat stroke
d) due to low temperature
The most widely recognized damage occurs due to UV radiations occurs to the
a) lungs
b) kidneys
c) eyes
d) skin
Explanation: skin burn, skin damage and skin cancer
