Which of the following is not used for putting out fires from electrical gadgets ?
sand
water
foam
carbon dioxide
B.
water
The calorific value of fuel is expressed in
joule
kJ/kg
kJ
none of the above
The burning of candle is an example of
spontaneous combustion
rapid combustion
slow oxidation
explosion
The zone of the candle flame which is moderately hot is called
non-luminous zone
luminous zone
inner dark zone
lowest blue zone
Which of the following causes acid rain ?
carbon dioxide
sulphur dioxide
carbon monoxide
oxides of sulphur and nitrogen