1.How does the power of a lens change if its focal length decreases to half? What is the unit of power of lens?
2.Mention the functions of the following reproductive parts in human beings:- (i) Fallopian tubes (ii) Testes.
3.Carbon has the tendency to form a large number of compounds. List the characteristics of carbon atom which makes it versatile in nature.
4.An Alpha particle moves from north to south in an external magnetic field and it experiences a force in downward direction. Find out the direction of magnetic field.
5.Mention two limitations of Mendeleev's classification of elements
6.Ionic compounds do not conduct electricity in solid state. Why?
7.How is the sex of child determined in human beings?
Answers
Answer:
1. Power is inversely proportional to the focal length. So if the focal length is decreases by half, power will become double. The unit of power of lens is dioptre
Answer:
2)FALLOPIAN TUBE :- FUNCTION - transport the ova from the ovary to the uterus but in presence of sperm and fertilization the fallopian tube transport the fertilized egg to the uterus for implantation.
TESTES :- FUNCTION - testes are responsible for the production of sperms .
3)carbon have atomic number 6 hence it's electronic configuration is 1s2 2s2 2p2 hence it's outer shell has has 2 unpaired electrons in group state whereas in exited state it possess 4 unpaired electrons, hence carbon have more tendency to form compounds .
5)No proper position could be given to the element hydrogen . the increasing order of atomic mass was not strictly followed throughout .