Practice Test - NEET MCQ

Since Potential difference between two points in equipotential surfaces is zero, the work done between two points in equipotential surface is also zero.

Definition based

Potential Energy of a System with One Point Charge

• Definition of Potential Energy: Potential energy is the energy stored in an object due to its position or configuration in a system.


• Potential Energy of a Point Charge: In the case of a system containing only one point charge, the potential energy of the system is considered to be zero.


• Explanation: When there is only one point charge in a system, there is no other charge or external force interacting with it to create potential energy. Therefore, the potential energy of a single point charge is considered to be zero.

This is why the correct answer is A: Zero.

1. Current: This is a general term for the flow of electric charge. It can refer to any type of charge flow, not specifically electrons.

2. Electronic current: This specifically refers to the flow of electrons through a conductor.

3. Conventional current: This is the flow of positive charge and is considered to flow from the positive side to the negative side of a power source. Historically, this was defined before the discovery of electrons, so it is opposite to the direction of electron flow.

4. Photonic current: This is not a standard term in electrical engineering or physics. It might refer to currents related to photons in some contexts, but it is not related to the flow of electrons.

So, if you are referring to the flow of electrons specifically, electronic current is the accurate term.

The connecting metal strips include a small resistance in the circuit called the end resistance.On reversing the current, the end resistance tends to get cancelled out.

The varactor diode is used in a place where the variable capacitance is required, and that capacitance is controlled with the help of the voltage. The Varactor diode is also known as the Varicap, Voltcap, Voltage variable capacitance or Tunning diode.

In a p-type semiconductor, the holes are the majority carriers, while the electrons are the minority carriers. A p-type semiconductor is obtained when trivalent atoms, such as aluminium, are doped in silicon atoms.

Binary number system, in mathematics, positional numeral system employing 2 as the base and so requiring only two different symbols for its digits, 0 and 1, instead of the usual 10 different symbols needed in the decimal system.

1001=1x2³+0x2²+0x2¹+1x2⁰=9
For binary numbers, the digit at the extreme right is referred to as least significant bit (LSB) and the left- most digit is called the most significant bit (MSB). Hence in binary 10010, the most significant bit is 1.
 

The correct answer is option D
Organic compounds are broadly classified into open chain and closed chain compounds. Explanation: open chain compounds or acyclic compounds are otherwise called as aliphatic compounds.

Acetic acid is a linear chain compound (acyclic) and hence it is not an example of ring compound (alicyclic).

Pyridine is heterocyclic aromatic compound. Whereas naphthalene and aniline are benzenoid aromatic compounds and tropolone is a non-benzenoid aromatic compound.

Termination is the last step. So there shouldn't be any free radical atom remaining. In first option there is Cl• remaining it can't be termination step.The steps in free radical halogenation are as

Free radical bromination reaction is highly selective, occurs mainly at the carbon where most stable free radical is formed.
We know that the stability of free radical is in the order,
Tertiary radical > Secondary radical > Primary radical
In (a), (b) and (c), the bromination occurs at secondary carbon whereas in (d) the bromination occurs at tertiary carbon. Since, tertiary radicals are more stable than secondary radical the major product of monobromination of ethyl cyclohexane is (d).
The stability of tertiary radical is due to the higher number of α−Hygrogens which give more hyperconjugation effect than secondary.

Correct Answer :- b

Explanation : The 2o hydrogens are 20 times more reactive than the 1o ones.

Bromination in the presence of light is done by free radical mechanism. The radical on the carbon chain is formed where the radical is most stable. We can’t put radical on the ring as the aromaticity of the ring will be lost. So, it should be put either on the CH₃. However, the CH₃ which is attached to NO₂ ring will not bear stable radical as NO will decrease the stability of radical.(NO₂ is an electron withdrawing group). So the only position is the other CH₃ in option d. There also we have stability due to resonance.

Hey fever or Allergic rhinitis is inflammation of nasal airways. It occurs when an allergen is inhaled by an individual with sensitive immune system.

Common cold and AIDS are viral disease caused by rhinovirus and HIV virus respectively.

Streptococcus pneumoniaea and Haemophilus influenza bacteria causes pneumonia in humans which infects the alveoli of the lungs and cause severe problem in respiration.

• Early detection of cancer is essential as it allows the disease to be treated successfully in many cases.
• Cancer detection is based on biopsy and histopathological studies of the tissue and the blood and bone marrow tests for increased cell counts in the case of leukaemias.

The primary and secondary immune response are carried out with the help of two special types of lymphocytes present in our blood called B-lymphocytes and T-lymphocytes.

Inflammation at the spot of insect bit is result of chemical released by the body such as histamine and kinins in response to chemical released by insect in the body.

The treatment of snake bite by anit-venom is an example of artificial acquired passive immunity. Anti-venom neutralize the effect of venom in the body.

The dough which is used for making foods such as dosa and idli is fermented by using bacteria like Streptococcus. The puffed-up appearance of this dough is due to the production of CO₂ gas.

• Propionibacterium sharmanii is responsible for the production of large holes in Swiss cheese. This is a process that occurs during the cheese's aging process.
• Propionibacterium sharmanii is a type of bacteria that can convert lactic acid into propionic acid, carbon dioxide, and water. This bacterium is specifically used in the production of Swiss cheese.
• During the cheese-making process, the cheese is warmed, which encourages the growth of Propionibacterium sharmanii. As the bacteria metabolize the lactic acid, they produce carbon dioxide gas.
• The carbon dioxide gas cannot escape the cheese, which is semisolid, leading to the formation of bubbles or holes within the cheese.
• As the cheese ages, the bacteria continue to produce gas, and the holes, or 'eyes', in the cheese continue to grow larger. The size of the holes can be controlled by adjusting the temperature and aging time of the cheese.

• Both statements 1 and 2 are correct. A small amount of curd added to the fresh milk as inoculum or starter contains millions of lab, which at suitable temperatures multiply, thus converting milk to curd.
• It improves its nutritional quality by increasing vitamin B₁₂. In our stomach too, the lab plays a very beneficial role in checking disease-causing microbes.

Rennet is extracted from the stomach of the calf and is used to prepare cottage cheese.

LAB stands for Lactic acid bacteria. Indian curd is prepared from both skimmed and cream milk by inoculating the milk with lactic acid bacteria.

Large holes in Swiss cheese are formed by the CO2 produced (causing holes) by a bacterium called Propionibacterium shermanii.

• Both a and r are true and r is the correct explanation of a the dough used for making bread is fermented by saccharomyces cerevisiae or commonly called baker’s yeast.
• CO₂ released during the process of fermentation gives a puffy appearance to a dough. It is used to make foods like idli, dosa, bread, etc.