Question : Silver halides are used in photographic plates because they are

Option 1: oxidised in air

Option 2: soluble in hyposolution

Option 3: reduced in light

Option 4: totally colourless

Question : A mirage occurs because of:

Option 1: reflction by hot ground

Option 2: total internal reflection by layers of air

Option 3: interference of light

Option 4: diffraction of light

Question : Which light is least effective in photosynthesis ?

Option 1: Blue light

Option 2: Green light

Option 3: Red light

Option 4: Sunlight

Question : The first metal used by man was 

Option 1: Aluminium

Option 2: Copper

Option 3: Iron

Option 4: Silver

Question : German silver is an alloy of

Option 1: Copper, nickel and silver

Option 2: Silver ,copper and aluminium

Option 3: Zinc copper and nickel

Option 4: Zinc silver and copper

Question : Which among the following metals is used for galvanisation?

Option 1: Zinc

Option 2: Copper

Option 3: Iron

Option 4: Silver