ATMOSPHERIC VISIBILITY

44.   Fog is reported when visibility is reduced to

a.    Less than 1000 m

b.      1000m

c.      1000 to 2000

45.   RVR is reported when visibility falls below

a.      500 m

b.      1000 m

c.    1500 m

d.      2000 m

46.   Radiation fog occurs

a.    Over land

b.      Over sea

c.      During day

47.   When visibility reduces between 5000 m and 1000 m and RH is almost 100%, it is

a.    Mist

b.      Haze

c.      Fog

48.   Radiation Fog forms over N India during

a.      May to June

b.    Dec to Feb

c.      Oct to Nov

49.   Warm and moist air moving over a cold ground gives rise to:

a.      Thunder  clouds

b.    Fog and stratus

c.      Frontal clouds

50.   Warm and moist air moving over a cold surface causes

a.      Radiation Fog

b.    Advection Fog

c.      Frontal Fog

51.   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

52.   The radiation fog activity increases after the passage of a...

a.    WD

b.      Depression

c.      Col

53.   Radiation fog is essentially a         phenomena

a.    Nocturnal

b.      Dusk

c.      Day

54.   The radiation fog forms over

a.      Water

b.    Land

c.      Both

55.   The    fog lorms due to horizontal movement of air

a.      Radiation

b.    Advection

c.      Frontal

56.   Advection fog forms during

a.      night only

b.      day time only

c.    any time of day and night

57.   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

58.   Instrument used for measuring visibility...

a.      Visiometer

b.    Transmissometer

c.      Ceilometer

59.   Advection fog forms

a.      over sea

b.      over Land

c.    both over land and sea