Technology indicates the level of cultural development of society. Human beings were able to develop technology after they developed better understanding of natural laws.

For Example:

(i) The understanding of concept of friction and heat helped us discover fire.

(ii) Understanding of the secrets of DNA ad genetics enabled us to conquer many diseases.

(iii) We use the laws of aerodynamics to develop faster planes.

Given, Constant electric field of magnitude of 4N/C is acting along the x - axis. we need to find the potential difference between the points - 2 to + 4. here as nothing is given we will take the given points/distances to be in S.I units. From the relation of Potential difference and electric field we know that,

Merits of external sources of recruitment :
(i) Qualified personnel An organisation can attract highly qualified personnel through external sources.
(ii) Wider choice External sources create a large pool of candidates to choose from, for the organisation.
(iii) Fresh talent External sources helps to bring fresh talent or new blood into the organisation.
(iv) Competitive spirit New entrants and qualified freshers creates competitive spirit and helps to improve performance.

Demerits of external sources of recruitment :
(i) Dissatisfaction among existing staff Recruitment from external sources may create dissatisfaction among the existing staff as their chances of promotion are reduced.
(ii) Lengthy process Recruitfnent from external sources involves a lot of time and efforts of the manager.
(iii) Costly process Recruitment from external sources involves a lot of expenditure on advertising, selection and other processes.

Rate of change of concentration ammonia = -0.2 * 10^-4 M/s

Explanation:

Given: N2+3H2 →2NH3. During the formation of ammonia 2 moles of nitrogen disappear in 1min. The volume of vessel is 1L.

Solution:

N2 + 3H2 -----> 2NH3

-d[H2] / dt = 0.3 * 10^-4 M/s

Rate = (1/3)(-d[H2] / dt)

        = (1/2) (d[NH3] /dt)

       = d[NH3] / dt

       = (2/3)( -d[h2]/dt)

       = d [NH3]/dt

d[NH3] /dt = -2/3 (0.3 * 10^-4)

 d[NH3] /dt = -0.2 * 10^-4 M/s

Rate of change of concentration ammonia is the answer.

As a supernational organisation, the European Union bears economic, political diplomacy and military influence as a regional organisation in the following manner:

1. Economic Influence:

•  Three times larger share in world trade than the US.
•  Its currency Euro, can pose a threat to the dominance of the US dollar.
•  The EU functions as an important bloc in the World Trade Organisation (WTO). 

2. Political and Diplomatic Influences:

•  Two members of the EU, Britain and France hold permanent seats in the Security Council to influence the UN policies.
•  The EU also includes various non-permanent members of the UNSC.
•  The European Union play an influential role in diplomacy and negotiations except the military force i.e. the EU’s dialogue with China on human rights and environmental degradation is remarkable.

We know that the charge on an electron is negative and it is -1.6⨯10^-19 coulomb.

We need to calculate the number of electrons constituting one coulomb of charge.

e = 1.6 × 10^-19 C

Total charge required for 1Coulomb.

∴  q = 1C……….(1)

The formula to calculate the charge is

q = ne

where

q = charge

e = number of electrons

n = q/e……….(2)

Substituting equation (1) in equation (2) we get

n = 1/(1.6 × 10^-19)

n = 6.25 × 10¹⁸ electrons ≅ 6 × 10¹⁸ electrons

So 1 Columb of charge contains 6 × 10¹⁸ electrons. 

A DC generator is an electrical machine whose main function is to convert mechanical energy into electricity. When conductor slashes magnetic flux, an emf will be generated based on the electromagnetic induction principle of Faraday’s Laws. This electromotive force can cause a flow of current when the conductor circuit is closed.

A DC generator is an electrical machine whose main function is to convert mechanical energy into electricity. When conductor slashes magnetic flux, an emf will be generated based on the electromagnetic induction principle of Faraday's Laws.

A n s w e r : Molecular crystal
E x p l a n a t i o n :
wax crystals are molecular crystals, in which constituent particles are molecules having inter particle forces are Vander Waal’s forces.

Find factorial using Python function – using for loop

#Pyton program to find factorial of a number

def factorial(num):#function definition

fact=1

for i in range(1, num+1):#for loop for finding factorial

fact=fact*i

return fact #return factorial

number=int(input("Please enter any number to find factorial: "))

result=factorial(number)#function call and assign the value to variable result

print("The factorial of %d = %d"%(number,result))

When the above code is executed, it produces the following results

Please enter any number to find factorial: 6

The factorial of 6 = 720

Find factorial using Python function – using while loop

def factorial(num):#function definition

fact=1;

i=1

while i<=num:

fact=fact*i

i=i+1

return fact

num=input("Enter a number..");

result=factorial(num)

print("factorial of the number: %d" %result)

factorial(num)#function call

When the above code is executed, it produces the following results

Enter a number..5

factorial of the number: 120

Programming approaches for implementing these program

• Take a number as input  from the user and stored in variable number for finding factorial
• Declare a python function to find factorial
• Inside the function, declare the variable fact and initialise as 1
•  Inside the function, find the factorial of a given number using for loop in Python
• Run the loop from given number until 1 and multiply numbers
• Call the factorial() function and assign the output to variable result
• the factorial of the given number is displayed using the print() function in Python

मूल बिन्दु की ओर नतोदर होता है। इसका कारण बढ़ती हुई सीमांत अवसर लागत है। उत्पादन सम्भावना वक्र में दायीं ओर खिसकाव संसाधनों में वृद्धि तथा तकनीकी प्रगति को दर्शाता है। उत्पादन सम्भावना वक्र बायीं ओर खिसकाव संसाधनों में कमी तथा तकनीकी अवनति को दर्शाता है।

AC Generator

• An electrical generator is a device that converts mechanical energy to electrical energy.
• The generation of alternating currents (ac) is based on the phenomenon of electromagnetic induction.
• Whenever the magnetic flux changes an emf will be induced in the coil.

• AC generator is a device that converts mechanical energy into electrical energy(alternating currents).
• AC generator is an example of inducing an emf or current in a loop by varying the magnetic field and area vector.

To calculate, GDPMP by, the expenditure method, we add up final expenditure on the goods and services produced by all the economic sectors of an economy. Expenditures incurred on consumption and investment are final expenditures. These are classified into: (i) Private final consumption expenditure. (ii) Government final consumption expenditure. (iii) Gross domestic capital formation. (iv) Net exports = (Exports less Imports) The sum total of these expenditures is GDPMP..

The expenditures approach says GDP = consumption + investment + government expenditure + exports – imports. The income approach sums the factor incomes to the factors of production. The output approach is also called the “net product” or “value added” approach .

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 Physics