A.Energy can be converted into matter but matter cannot be converted into energy
B.Matter can be converted into energy but energy cannot be converted into matter
C.Energy and matter both can be converted into each other
D.Neither energy can be converted into matter nor can matter be converted into energy
A.exothermic reaction
B.endothermic reaction
C.thermo-chemical reaction
D.photochemical reaction
A.? H = Q + Ws
B.?H = Q-Ws
C.?U = Q-Ws
D.?U = Q + Ws
A.nucleus is positively charged
B.nucleus is the centre of atom
C.?-rays are deflected by nucleus
D.almost whole of the mass is concentrated in nucleus
A.A hard wood board
B.A porcelain sheet
C.An asbestos sheet
D.Saw dust
A.pv2/2
B.v2/2
C.v
D.v2/2g
A.Voltaic cell uses exothermic chemical reactions to produce electrical energy
B.In the voltaic cell the positive current flows from the positive electrode to the negative electrode outside the cell
C.A voltaic cell can become an electrolysis cell by use of an external voltage greater than the voltaic cell voltage and imposed in the opposite directions
D.Voltaic cell uses electrical energy to produce endothermic chemical changes
A.Enzyme fermentation reactions
B.Microbial fermentation reactions
C.Photochemical reactions
D.Synthesis of ammonia.
A.?20? to 1600?C
B.300? to 1100?C
C.800? to 2000?C
D.?20? to 300?C
