Answer:
(a) The force between them quadruples
Explanation:
According to coulomb's law, initial force between the two charged objects is given as;

where;
k is coulomb's constant
q₁ is the charge on the first object
q₂ is the charge on the second object
r is the distance between the two objects
When the charges on both objects are doubled, then;
q₁ = 2q₁
q₂ = 2q₂
Force between the two charged objects will become

Therefore, the force between them quadruples
Answer:
hi is
Explanation:
Ans. (1) For preparing vaccines, in olden days,microbes were injected in the bodies of horses ormonkeys. These laboratory animals used to makeantibodies to defend these microbes. Antibodies areproteins which can act against the disease-causinggerms. These antibodies were extracted from theblood of these animals and were used as vaccines.(2) Now-a-days with the advent of biotechnology,the vaccines are manufactured in laboratories withthe help of bacteria. For this purpose, a detailedstudy of the disease causing germ is undertaken.The genes and the DNA of such microbes arethoroughly explored. Then based on thisinformation, proteins which can act against suchmicrobes are synthetically prepared in thelaboratories. The safe vaccine is produced in such away which can defend the body against infections.3) Some types of vaccines are prepared from theextracts of germs. These germs or microbes aredeactivated and made dormant. When they areinjected in the body of a person, they initiate thedefending action. The body of such vaccinatedperson, already develops the antibodies in his or herbody. When in future, this person is again attackedby similar germs the defence starts immediately andthe person does not become sick.
Answer:
Because as the waves propagates, the particles of the medium (molecules of water) vibrates perpendicularly (upward and downward) about their mean position and not in the direction of the waves.
Explanation:
A wave is a phenomena which causes a disturbance in a medium without any permanent deformation to the medium. Examples are; transverse wave and longitudinal wave. Waves transfer energy from one point in the medium to another.
The waves generated by water are transverse waves. Which are waves in which the vibrations of the particles of the medium is perpendicular to the direction of propagation of the waves.
Thus as the waves propagates, the molecules of water vibrates up and down and not along the direction of propagation of the waves. So that the floating objects do not get pushed in the direction of the waves every time.