Because Any object or substance that is less dense than a fluid will float in that fluid, so hot water rises (floats) in colder water. When fluids are cooled, they contract and therefore become more dense. Any object or substance that is more dense than a fluid will sink in that fluid, so cold water sinks in warmer water
Answer:
4.9 eV .
Explanation:
It is the case of discharge through mercury tube light . In it , mercury atoms are exited due to which electrons are sent to higher energy level . Here current drops to zero because electrons are excited to higher level . Energy are absorbed in quantised manner . Energy absorbed by electrons will be 4.9 eV . That means , difference in energy between two energy level is 4.9 eV .
Answer:
Voltage in the primary winding of the coil is 3.9 V
Explanation:
As we know by the principle of transformer we have

here we know that



now we have

