According to Gauss’s law, the total of the electric flux out of a closed surface is equal to the charge enclosed divided by the permittivity. The total electric flux through a closed surface is zero if no charge is enclosed by the surface.

• Gauss’s law is true for any closed surface, no matter what its shape or size.
• The term q on the right side of Gauss’s lawincludes the sum of all charges enclosed by the surface. The charges may be located anywhere inside the surface.
• In the situation when the surface is so chosen that there are some charges inside and some outside, the electric field [whose flux appears on the left side of Eq. (1.31)] is due to all the charges, both inside and outside S. The term q on the right side of Gauss’s law, however, represents only the total charge inside S.
• The surface that we choose for the application of Gauss’s law is called the Gaussian surface. The Gaussian surface can pass through a continuous charge distribution.
• Gauss’s law is useful for the calculation of the electrostatic field for a symmetric system.
• Gauss’s law is based on the inverse square dependence on distance contained in the Coulomb’s law. Any violation of Gauss’s law will indicate departure from the inverse square law.

The system in which goods are directly exchanged without the use of money.

The limitations of the barter system:

(i)Lack of Double Coincidence of Wants: Barter system can work only when both buyer and seller are ready to exchange each other’s goods.

(ii)Lack of Common Measure of Value: In the barter system, all commodities are not of equal value and there is no common measure (unit) of value of goods and services, in which exchange ratios can be expressed. 

(iii)Lack of Standard of Deferred Payment: The borrower may not be able to arrange goods of exactly same quality at the time of repayment.

On July 7, HRD Minister Ramesh Pokhriyal announced a major CBSE syllabus reduction with 30% of the syllabus slashed for the year 2020-21 for classes 9 to 12 because of the reduction in classroom teaching time due to the Covid-19 pandemic and lockdown.

CBSE has rationalized the syllabus with the help of suggestions from NCERT and the same has been notified by a new CBSE notification as well.

Deleted syllabus of CBSE Class 12 Mathematics

Objectives of planning:

a. To keep control over all activities which suggests that planning & control are connected with each other.

b. it also helps in keeping a good control in organizing a tournament.

c. b. Reduce the chances of mistake

d. It suggests programmes can be conducted with proper coordination with least mistakes rather focusing on success.

e. To promote innovative ideas.

f. To provide direction towards the goal

g. To reduce undue pressure

h.To provide proper co-ordination among the committees.

HRD Minister Ramesh Nishank announced a major CBSE syllabus reduction for the new academic year 2020-21 on July 7 which was soon followed by an official notification by CBSE on the same.

Considering the loss of classroom teaching time due to the Covid-19 pandemic and lockdown, CBSE reduced the syllabus of classes 9 to 12 with the help of suggestions from NCERT.

The CBSE syllabus has been rationalized keeping intact the learning outcomes so that the core concepts of students can be retained.

Deleted syllabus of CBSE Class 12 Mathematics

D

Electric field at point on equatorial line of an electric dipole.

Consider on electric dipole consisting of two point-charges +q and –q separated by distance 2a.

Let P be a point at a distance r from the center of the dipole on the equatorial line, where the electric field is to be calculated.

Let E₁ be electric field intensity at P due to charge –q. Therefore,

From right-angled triangle AOP, we have AP = √r² + a² . Therefore, 

The direction of Vector E₁ is along PA.

Now, let E₂ be electric field intensity at P due to charge +q.

From right-angled triangle BOP, we have BP = √ r² + a².There fore,

The direction of E₂ is along BP.

The resultant electric field Vector E is the difference of the two fields:

Thus, the electric potential due to electric dipole is zero at every point on the equatorial line of the dipole.

Harrold M. barrow examined the general motor fitness of college men and declared the norms for grading the individual. The three test item included are:- 

(a) Zig-Zag Run 

(b) Standing broad jump. 

(c) Medicine ball throw 

(a) Zig-Zag Run: 

Purpose: To test power, speed, quickness and body control in multiple planes of movement. The test also assess lower extremity control. 

Equipment: Measuring tape, two stop watches, five cones 

Procedure: 

(i) Set up the path, which is 3 by 4.85 m and marked with coloured tape on the floor, and place cones in every corner. 

(ii) Subject stands behind starting line. On the signal "Ready go" the subject start running in zig-zag way. 

(iii) The subject runs one lap as fast as possible around the zig-zag path. 

(iv) If the subject does not round all cones in completing the one full lap. require him/her to rest and then Retest is done. 

(v) Record the time to perform one full lap around the path to the nearest tenth of 9 second. 

Scoring: Time taken to finish zig-zag run and as per the norms grading is done.

(b) Standing long/broad jump: 

Purpose: To measure explosive power of the legs. 

Equipment: Measuring tape, non-slipery floor, mat 

Procedure: 

(i) Stand behind marked starting line. 

(ii) Feet slightly apart

(iii) Swing your arms back and forth rthymically and bend the knees. 

(iv) The athlete takes off and lands using both feet, arm swing and bend knees provide forward drive. 

(v) The subject attempts to land as far as possible. 

(vi) Landing on both the feet without falling backwards. 

(vii) Three attempts are allowed 

Scoring: The measurement is taken from take offline to the nearest point of contact on the landing (Back of the heels). The best of three attempt is recorded and as per rating scale grading is done. 

(c) Medicine Ball throw test 

Purpose: To measure upper body strength and explosive power. 

Equipment: Medicine ball for Boys 3 kg and for girls 1 kg, measuring tape, safe place and an Assistant. 

Procedure: 

(i) Warm up thoroughly 

(ii) Stand with both feet behind a marked line 

(iii) Hold the ball overhead with two hands. 

(iv) Throw the ball as far as possible. 

(v) Take three attempts and record the best score. 

Scoring: Measure the distance covered by the subject and as per the norms grading is done. 

<font face="Arial Narrow">RNA replication is the process by which new copies of genome-length RNAs are made
RNA replication occurs in the cytoplasm and is carried out by the viral RNA polymerase.
The full length plus strand is coated with nucleocapsid protein as it is made (mRNAs are not coated with this protein, which would interfere with the host protein translation machinery).</font>

<font face="Arial Narrow">The new positive strand is copied into full length minus strand, which is also coated with nucleocapsid protein as it is made. (Note: since the viral RNA polymerase synthesizes  mRNAs (transcription) and full-length RNA (replication), it is also sometimes called a transcriptase or a replicase, such names just focus on the different aspects of the polymerase activity.)</font>

Reproduction is a biological process of formation of new offsprings from the pre-existing organism. Reproduction becomes a vital process without which species cannot survive for long It ensures continuity of species generation after generations as older individuals undergo senescence and ultimately they die.

Life span – • The period from birth to the natural death of an organism represents its life span. Life span of organisms varies from few days (Butterfly-1to 2 weeks) to thousands of years (Banyan tree).

Types of Reproduction:
Based on whether there is one or two organisms taking part in the process of reproduction

• ASEXUAL REPRODUCTION
• SEXUAL REPRODUCTION

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<a data-ved="2ahUKEwj0_c3L69ztAhX_7HMBHUpWAXAQFjABegQIAhAC" href="https://mycbseguide.com/blog/reproduction-organisms-class-12-notes-biology/" ping="/url?sa=t&source=web&rct=j&url=https://mycbseguide.com/blog/reproduction-organisms-class-12-notes-biology/&ved=2ahUKEwj0_c3L69ztAhX_7HMBHUpWAXAQFjABegQIAhAC" rel="noopener" target="_blank">Reproduction in Organisms class 12 Notes Biology ...</a>

DNA replication is the biological process in which two identical copies of DNA are produced from one original DNA molecule.
The steps involved in the process of DNA replication are as follows:

1. The first step in DNA replication is to ‘unzip’ the double-helix structure of the DNA molecule.
2. This is carried out by an enzyme called helicase which breaks the hydrogen bonds holding the complementary bases of DNA together (A with T, C with G).
3. The separation of the two single strands of DNA creates a ‘Y’ shape called a replication ‘fork’. The two separated strands will act as templates for making the new strands of DNA.
4. One of the strands is oriented in the 3’ to 5’ direction (towards the replication fork), this is the leading strand. The other strand is oriented in the 5’ to 3’ direction (away from the replication fork), this is the lagging strand. As a result of their different orientations, the two strands are replicated differently.

I M R stands for Infant Mortality Rate

Infant Mortality Rate (or IMR) indicates the number of children that die before the age of one year as a proportion of 1000 live children born in that particular year.

1. urge the departure - insist on the going away of the British from India

The mitotic division called cleavage starts as the zygote moves through the isthmus of the oviduct towards the uterus and forms 2, 4, 8, 16 daughter cells called blastomeres. The embryo with 8 to 16 blastomeres is called a morula. The morula continues to divide and transforms into blastocyst as it moves further into the uterus. The blastomeres in the blastocyst are arranged into an outer layer caned trophoblast and an inner group of cells attached to trophoblast called the inner cell mass.

Firozabad had not changed with time because the years of mind-numbing toil had killed all initiative and the ability to dream for a change. The cry of not having money to do anything except carry on the business of bangle making and not having enough to eat rang out in every home. The young men echoed the lament of their elders but little could change because they had lost the ability to hope for it. As a result, the place recorded no progress.

The metaphor of the rattrap signifies that the world exists only to trap people by setting baits for them. Whenever someone is tempted by the luxuries, he ends up being caught in a dangerous trap. The author, thus, makes a much deeper comment on the woeful plight of those in pursuit of the worldly pleasures, which often lead them to unfortunate situations. The story helps in realising the importance of general goodness and kindness. The peddler is saved from the snare of the huge rattrap called world only when he appreciates the kindness to him by Edla.

Answer:

Pablo Neruda wishes for that exotic moment when mankind will be free from greed, cruelty and harmful actions. Unnecessary rush and noise have caused unpleasantness and troubles. The poet wishes the noise of engines and machines should cease and peace and tranquility should prevail.