What is the primary function of $Cu$ ions released by $IUDs$?

Oral contraceptive pills are taken daily for a period of $...$ days. After a gap of $...$ days,this process is repeated until the woman desires to prevent conception.

Which of the following is a hormone-releasing intrauterine device $(IUD)$?

Which of the following is a second-generation $IUD$?

$A$: Periodic abstinence is a natural method of contraception in which couples avoid or abstain from coitus from day $10$ to $17$ of the menstrual cycle,when ovulation is expected.
$R$: Day $10$ to day $17$ of the menstrual cycle is considered a safe period.

What is true about 'Saheli'?
$I$. Developed at $CDRI$,Lucknow
$II$. Contains a steroidal preparation
$III$. 'Once-a-week' pill
$IV$. Many side effects
$V$. High contraceptive value
$VI$. Very few side effects
$VII$. Low contraceptive value