Monthly Mock Test (November 30) - NEET MCQ

Potential at the centre of the sphere
= potential on the surface = 80 V.

Charge on each plate of each capacitor

Q = CV =  25 x10^-6 x 200
= 5 x10^-3C

Energy stored in capacitor

Charge Q = C₁V
Total capacity of combination (parallel)

C = C₁+ C₂

Potential at C = V_C = 0
Potential at D = V_D

Potential difference

Distance of point A from the two +q
charges = L.
Distance of point A from the two –q
charges =

Potential at B, V_B is maximum
V_B > V_C > V_A
As in the direction of electric field
potential decreases.

Diamond is an insulator.

With out losing its concentrati on Zn Cl₂ solution can not kept in contact with Al because Al is more reactive than Zn due to electrode (reduction) potential.

For bottom of ship to be protected it is connected with more reactive metal than iron like magnesium. This technique is called cathodic protection.

In the silver plating of copper, K[Ag(CN)₂] is used instead of AgNO₃. Copper being more electropositive readily precipitate silver from their salt solution

whereas in K[Ag (CN)₂] solution a complex anion [Ag(CN)₂]^– is formed and hence Ag+ are less available in the solution and therefore copper cannot displace Ag from its  complex ion.

The cell reacton is as follows :

(c) is correct answer.

For a concentration cell having different concentrations of ions.

If all the concentrations are identical then obviously the cell voltage is zero. But as the pH of 0.1 M HCl (strong acid) & pH of 0.1M CH₃ COOH is (weak acid) not same, therefore the cell voltage is not zero.

By Faraday's Ist Law, 

(where q = it = charge of ion) we know that no of equivalent

(where i= 1 A, t = 16×60+5 = 965 sec.) Since, we know that

Normality 

= 0.01 N

Relaxin is produced first by the corpus luteum of the ovary and later by the placenta. It helps in parturition as it increases the flexibility of the pubic symphysis and helps dilate the uterine cervix.

• The sperms in the female’s genital tract are made capable of fertilising the egg by secretions of the female genital tract.
• These secretions remove coating substances deposited on the surface of the sperms particularly those on the acrosome
• Thus the receptor sites on the acrosome are exposed and sperm becomes active to penetrate the egg. 
• This phenomenon of sperm activation in mammals is known as capacitation.

It is made almost exclusively in the placenta. HCG hormone levels found in the mother's blood and urine rise a lot during the first trimester. They may play a part in the nausea and vomiting often linked to pregnancy.

• Prolactin is the hormone which induces lactation (enables females to produce milk) and has no role in parturition.
• Parturition is a phenomenon of giving birth. It is a process of delivering a child from the womb to the outside. It is usually initiated by the release of oxytocin hormone. 
• This hormone increases the contraction of uterine muscles. Prostaglandins are synthesized and released in response to the oxytocin hormone. Also, an increase in estrogen and progesterone ratio indicates the initiation of the parturition process.

• GIFT (Gamete Intra Fallopian Transfer) is a technique helping to have a child.
• Gamete Intra Fallopian Transfer (GIFT) is an assisted reproductive technology in which both the sperm and unfertilised oocytes are transferred into the Fallopian tubes. Fertilisation takes place in vivo (inside the body of the female).

Gamete intra fallopian transfer:

Urethra is a tube that connects the urinary bladder to the genitals for the removal of fluids from the body. The urethra travels through the penis and carries semen as well as urine.

Synthesis of estrogen and progesterone due to high level of hCG is a normal gonadotropic activity in a normal pregnant female. 

• Human chorionic gonadotropin is the embryonic hormone, which ensures the corpus luteum continues to produce progesterone throughout the first trimester of pregnancy.  
• As well as maintaining progesterone production from the ovary, human chorionic gonadotropin may also play a role in making sure the lining of the uterus (endometrium) is ready to receive the implanting embryo. hCG may also promote the production of other steroids (e.g., estrogen) and protein (e.g., relaxin, inhibin A) hormones whose actions in the uterus may facilitate gestation.
• So, the correct answer is 'High level of hCG stimulates the synthesis of estrogen and progesterone.'

The testes are present in the scrotum which maintains the scrotal temperature below 2ºC of the internal body temperature.

Acrosome a small pointed structure at the tip of nucleus. It breaks down just before fertilization, releasing hydrolytic enzymes that assist penetration between follicle cells that surrounds the ovum, thus facilitating fertilization.

Parturition is the process of delivery of the foetus. The signals for parturition originate from the fully developed foetus and placenta that induce uterine contraction called foetal ejection reflex. This triggers the release of oxytocin hormone from pituitary. This in turn leads to expulsion of the baby out of uterus.

In vitro fertilization (IVF) or test-tube baby technique involves fertilizing one or more eggs outside the body and then transferring the fertilized eggs known as pre-embryos back into the uterus. Zygote Intra Fallopian Transfer (ZIFT) is an example of IVF. In this, the zygote or early embryos upto 8 blastomeres are transferred into the Fallopian tube. If the embryo has more than 8 blastomeres then it is transferred into uterus called as IUT.

A high blood concentration of progesterone and oestrogen will delay or stop menstruation. A high concentration of sex hormone inhibits ovulation and implantation, as well as alter the quality of cervical mucus to prevent / retard entry of sperms. This happens because high concentration of circulating progesterones are an indication of successful conception and pregnancy. Hence, secretion of follicle stimulating hormone (FSH) and luteinizing hormone (LH) from pituitary is inhibited.

Seminal plasma is composed of the fluid and sperms from the vas deferens. The major components of the seminal plasma in the male reproductive system are mucus, spermatozoa, and various secretions of accessory glands. The seminal plasma is rich in fructose, calcium, ascorbic acid, and certain enzymes. It provides nourishment and protection to sperms.

Amnion is an extraembryonic membrane in human prevents desiccation of the embryo inside the uterus. Amnion is a membrane that encloses the embryo of reptiles, birds and mammals within the amniotic cavity. This cavity is filled with amniotic fluid, in which the embryo is protected from dessication and from external pressure. 

The secretions of the acrosome help the sperm enter into the cytoplasm of the ovum through the zona pellucida and the plasma membrane. ... It is known as acrosomal reaction. Acrosome reaction results in dissolving of corona cells and degeneration of zona pellucida which helps in sperm penetration.