Physics
Specific gravity is defined as the ratio of

Density of the substance to the density of water at 0°C
Density of the substance to the density of water
Density of water at 4°C to the density of the substance
Density of the substance to the density of water at 4°C

ANSWER DOWNLOAD EXAMIANS APP

Physics
Lightning is produced when

Strong opposite charges in different clouds break down the resistance offered by the intervening air
Similar charges of electricity rush towards each other and then get repelled
Water vapour produces electricity in the clouds
Clouds strike against impurities in air and the friction burns up these impurities

ANSWER DOWNLOAD EXAMIANS APP