please help me.. army or anyone
Answers
Heyy Army!!!....Your answer is......
Answer:
Ans 21:
1. Diaphragm
A diaphragm is a barrier method of contraception that a person places inside the vagina. It is important to apply spermicide to the diaphragm before each use.
When used with spermicide, the CDC estimate that the diaphragm is close to 90 percent effective.
A person must insert the diaphragm a few hours before intercourse, leave it in place for 6 hours after sex, and remove it after 24 hours. Diaphragms do not protect against STIs.
2. Cervical cap
A cervical cap (sold as FemCap in the United States) is a soft silicone cup that is placed deep inside the vagina. It covers the cervix to stop sperm from reaching an egg.
This effectiveness of the cervical cap varies according to sources, but Planned Parenthood estimate that its effectiveness ranges from about 70 to 85 percent. It does not protect against STIs.
3. Sponge
The contraceptive sponge is a method of birth control that a person can buy without a prescription. Made of polyurethane foam and containing spermicide, the sponge is placed deep inside the vagina to block entry to the uterus.
Used alone, the sponge is 76 to 88 percent effective, but using it with a condom further reduces the risk of pregnancy.
Ans 21:
We prefer a convex mirror as a rear-view mirror in vehicles because it gives a wider field of view, which allows the driver to see most of the traffic behind him. Convex mirrors always form a virtual, erect, and diminished image of the objects placed in front of it.
Ans: 22
P = +1.5 D
f = 1/P = 1/+1.5 = 0.67 m.
As the power of lens is (+ve), the lens is converging lens.
I hope it might help you!!
Take care and stay safe!
I purple you!!❤❤❤