Formation of day and night is a _________ change.
slow
Fast
man made
none of these
A change harmful to us is a _______ change.
Undesirable
Desirable
Slow
The changes which are brought and controlled by man is called
Natural changes
Nan made changes
Chemical changes
Physical changes
The bacteria which is involved in curdling of milk is
Lactobacillus
Streptococci
Bacillus cereus
None of these
Heart beat is a _________ change.
None periodic
Periodic
Reversible
Irreversible change.
Curdling of milk is an __________ reaction.
endothermic
exothermic
both A&B
___________is the chemical reaction in which heat and light are formed in the form of flame.
Burning
Melting
Rusting of iron
Sublimation.
The changes which repeat themselves at regular intervals of time are called __________ changes.
Non periodic
Burning of a match stick is ____________ change.
fast
undesirable
Periodic change may be used for measuring
Time intervals
Fixed intervals
Prolonged intervals
Regular intervals.
