Mention some of the causes, both social and environmen-tal, that work behind the development of drug addiction .

Mention the symptomss of drug addiction.

Mention some causes of mental problem.

Answer the following questions: Mention some main factors behind seasonal variations of time series.

Go through the following statement (i) Relaxin produced by the ovary, facilitates delivery of the foetus by softening the connective tissue of pubic symphysis and relaxing the pelvic ligaments and joints. (ii) By the end of fifth month of pregnancy, the foetus develops limbs and digits. (iii) Thalidomide is a teratogenic drug which causes a condition called phocomelia. (iv). Although the levels of prolactin are high during pregnancy, milk secretion does not occur because of the high oestrogen and progesterone levels which make the breast unresponsive to the prolactin. Which of these are correct?

Some quantity of gas having a mass of 5 gm is heated from 10^@C to 100^@C . If heat is supplied in constant volume and in constant pressure separately, then find out the change in internal energy in both the cases, Also calculate the work done when the pressure is kept constant. C_V=0.153 cal//gm"^@C and C_P=0.217 cal//gm"^@C

In an ideal crystal, the entropy of the constituents at absolute zero temperature (0K) is zero. However, the crystals generally suffer from certain defects also called imperfections They may be both electronic and atomic in nature. The atomic imperfections may be stoichiometric (Schottky and Frenkel defects) or non-stoichiometric (metal excees and metal deficiency defects). In addition to these, there are impurity defects which are caused by the addition of certain impurities of metals and this is known as dopping. The dopping leads to semi conductors which may be either n-type or p-type in nature. Zinc oxide (ZnO) is white when cold and yellow when hot. It is due to the development of :