Sometimes , a crackling sound is heard while taking off a sweater during winters. Explain.

Sometimes, a crackling sound is heard while taking off sweater during winters. Explain.

Some varieties of wheat are knows as spring wheat while other are called winter wheat. Former variety is sown and planted in spring and it harvested by the end of the same season. However, winter varieties, if planted in spring, fail to flower or produce mature grains within a span of a flowering seasons. explain, why?

During summers in India, one of the common practice to keep cool is to make ice balls of crushed ice, dip it in flavored sugars syrup and sip it. For this a stick is inserted into curshed ice and its squeezed in the palm to make it into the ball. Equivalently in winter, in those areas where it snows, people make snow balls and throw around. Explain the formation of ball out of crushed ice or snow in light of P-T diagram of water.

A train travels between two stations ambala and Amritsar. While goind from Ambala to Amritsar, it takes 3 hours and its average speed is 100km/hr. when coming back from Amritsar of Ambala, it takes 2 hours and it average speed is 150 km/hr. obtain the average speed during the whole journey?

While filling up of electrons in the atomic orbitals, the 4s orbital is filled before the 3d orbital but reverse happens during the ionisation of the atom. Explain why?