Visibility and Fog Flashcards
Fog is reported when visibility is reduced to
> (a)Less than 1000m
(b)1000m
(c)1000 to 2000
RVR is reported when visibility falls below
(a) 500 m
(b) 1000 m
>(c) 1500 m
(d) 2000 m
Radiation fog occurs
> (a) Over land
(b) Over sea
(c)During day
When visibility reduces between 5000 m and 1000 m and RH is almost 100%,it is
> (a) Mist
(b) Haze
(c) Fog
Radiation Fog forms over N India during
(a) May to June
>(b) Dec to Feb
(c) Oct to Nov.
Warm and moist air moving over a cold ground gives rise to:
(a) Thunder clouds
>(b) Fog and stratus
(c) Frontal clouds
Warm and moist air moving over a cold surface causes
(a) Radiation Fog
>(b) Advection Fog
(c) Frontal Fog
The radiation fog forms due to
(a) Heating of the earth during day
>(b) Radiational cooling of earth at night
(c) Advection of cold air
The radiation fog activity increases after the passage of a ……….
> (a) WD
(b) Depression
(c)col
Radiation fog is essentially a ……….. phenomena
> (a) Nocturnal
(b) Dusk
(c)Day
The radiation fog forms over
(a) Water
>(b) Land
(c) Both
The ………. Fog forms due to Horizontal movement of warm moist air over cold surface
(a)Radiation
>(b) Advection
(c) Frontal
Advection fog forms during
(a) night only
(b) day time only
>(c) any time of day and night
For formation of Radiation fog
(a) There should be sufficient moisture in atmosphere, cloudy sky, nil wind
>(b)There should be sufficient moisture in atmosphere, clear sky, light wind.
(c)There should be sufficient moisture in atmosphere, cloudy sky, strong wind.
Instrument used for measuring visibility is called
(a) Visiometer
>(b) Transmissometer
(c) Ceilometer
