CBSE > Class 12 | CBSE Board | Homework Help

Physics Chemistry Biology Mathematics Applied Maths Accountancy Economics Business Studies English Core हिंदी कोर History Political Science Geography Sociology Psychology Physical Education Computer Science Informatics Practices Painting Legal Studies Entrepreneurship Home Science Reasoning & Mental Ability गणित रसायन विज्ञान जीव विज्ञान भौतिक विज्ञान लेखाशास्त्र मनोविज्ञान अर्थशास्त्र व्यवसाय अध्ययन English Elective NCERT हिंदी ऐच्छिक इतिहास राजनीति विज्ञान भूगोल समाजशास्त्र Engineering Graphics गृह विज्ञान शारीरिक शिक्षा Multimedia and Webtech English Elective CBSE (Deleted) संस्कृत कोर (भास्वती) संस्कृत ऐच्छिक (शाश्वती) Philosophy (Deleted) Biotechnology Financial Market Management Other Subjects Information Technology (802) Regional Language

Ask questions which are clear, concise and easy to understand.

Ask Question

R1 in a lens is positive or negative?

Posted by Tushar Dulloo 1 year, 6 months ago

CBSE > Class 12 > Physics

1 answers

Krish Agrawal 1 year, 5 months ago

The sign conventions for the radii of curvature (R1 and R2) for lenses are as follows: 1. **Convex Lens (Diverging Lens)**: - R1 (the radius of curvature of the first surface) is considered positive if the center of curvature is on the same side as the incident light (opposite to the direction of incoming light). - R2 (the radius of curvature of the second surface) is considered negative. 2. **Concave Lens (Converging Lens)**: - R1 (the radius of curvature of the first surface) is considered negative. - R2 (the radius of curvature of the second surface) is considered positive if the center of curvature is on the same side as the incident light (opposite to the direction of incoming light). These conventions are used in lens formula and mirror formula calculations to determine the sign of focal lengths and object distances.

0Thank You

ANSWER

What is lantanoid contraction

Posted by Charan Teja 1 year, 6 months ago

CBSE > Class 12 > Chemistry

1 answers

Keshav Chauhan 1 year, 3 months ago

When we move from 3d to 4d and 4d to 5d... The electrons start to be filled in the f subshell. As the screening power of the electrons of the f subshell is very poor, that's why there is regular decrease in the atomic radii of these elements, this is called lanthanoid contraction

0Thank You

ANSWER

What does the phrase 'to skin me' mean

Posted by Kashish Pathania 1 year, 6 months ago

CBSE > Class 12 > English Core

0 answers

ANSWER

Contribution of John marshal and martimer wheeler in Indian archaeology

Posted by Supriya Nath 1 year, 6 months ago

CBSE > Class 12 > History

1 answers

Kaal Lu 1 year, 5 months ago

John Marshall and Mortimer Wheeler made significant contributions to Indian archaeology: 1. **John Marshall**: - Marshall was the Director-General of the Archaeological Survey of India (ASI) from 1902 to 1931. He played a crucial role in systematizing archaeological research in India. - Under his leadership, the ASI conducted extensive excavations at various sites, including Mohenjo-Daro and Taxila, leading to the discovery of the Indus Valley Civilization. - He emphasized the importance of preservation and documentation of archaeological finds, which laid the foundation for modern archaeological practices in India. 2. **Mortimer Wheeler**: - Wheeler succeeded Marshall as the Director-General of ASI. He brought innovative techniques to Indian archaeology. - Wheeler introduced the grid system for excavations, which improved the accuracy of documenting findings and stratigraphy. - His work at sites like Harappa and Arikamedu furthered our understanding of India's ancient history. - Wheeler also emphasized the training and involvement of Indian archaeologists in excavation work, contributing to the development of a skilled workforce in the field. Both Marshall and Wheeler made substantial contributions to the study of India's archaeological heritage and its history.

1Thank You

ANSWER

Trace the technologies that were used for making beads by Harappans.

Posted by Mahem Bankai 1 year, 6 months ago

CBSE > Class 12 > History

0 answers

ANSWER

Devjyoti Bravia answers

Posted by Rohan Rajput 1 year, 6 months ago

CBSE > Class 12 > English Core

1 answers

Jahangir Alom 1 year, 6 months ago

2+3

2Thank You

ANSWER

Author name of the poem kepping quiet

Posted by Harkirat Kaur 1 year, 6 months ago

CBSE > Class 12 > English Core

2 answers

Kashish Gurawalia 1 year, 5 months ago

Pablo Naruda poet of poem keeping quiet

1Thank You

Jasleen Gill 1 year, 6 months ago

Pablo Naruda

1Thank You

ANSWER

Imagine you are Hana narrate the chapter from your point of view

Posted by Pronay Das 1 year, 6 months ago

CBSE > Class 12 > English Core

0 answers

ANSWER

did the people at Gemini studios have any particular political affiliations

Posted by Naresh Choudhary 1 year, 6 months ago

CBSE > Class 12 > English Core

0 answers

ANSWER

Mr lamb stands as a symbol of optimism and hope support your answer with example from the text

Posted by Subhanshu Sharma 1 year, 6 months ago

CBSE > Class 12 > English Core

0 answers

ANSWER

MCQ Qunestion

Posted by Harshit Bhargava 1 year, 6 months ago

CBSE > Class 12 > Economics

1 answers

Tarun Kumar 1 year, 6 months ago

What is moter devlopment

4Thank You

ANSWER

In what ways do you think that the Western Indian manuscript painting tradition guided the development of miniature painting traditions in Rajasthan

Posted by Krishna Kant Gaur 1 year, 6 months ago

CBSE > Class 12 > Painting

0 answers

ANSWER

In what ways do you think that the western Indian

Posted by Krishna Kant Gaur 1 year, 6 months ago

CBSE > Class 12 > Painting

0 answers

ANSWER

Question 1: A lens has a refractive index of 1.5 and a radius of curvature of 15 cm for one surface and 20 cm for the other surface. Calculate the difference in curvature between the two surfaces using the lens maker's formula Question 2: A concave lens with a refractive index of 1.4 is required to have a focal length of -12 cm. Determine the radil of curvature for the two lens surfaces using the lens maker's formula. Question 3: A biconvex lens with a refractive index of 1.6 has a known focal length of 25 cm. Calculate the difference in radii of curvature for its two surfaces using the lens maker's formula. Question 4 (Easy): A plano-concave lens has a refractive index of 1.2. The radius of curvature of the curved surface is 18 cm, and the flat side has a radius of curvature of infinity, Calculate the focal length of the lens using the lens maker's formula. Question 5 (Easy): A converging lens has a refractive index of 1.6. The radius of curvature of one surface is 12 om, and the radius of curvature of the other surface is 15 cm. Calculate the focal length of the lens using the lens maker's formula.

Posted by Tushar Dulloo 1 year, 6 months ago

CBSE > Class 12 > Physics

1 answers

Krish Agrawal 1 year, 5 months ago

To answer each of your questions, we can use the lens maker's formula, which is given by:

$\frac{1}{f} = (n - 1) \left( \frac{1}{R_1} - \frac{1}{R_2} \right)$ Where: -

$f$ is the focal length of the lens. -

$n$ is the refractive index of the material. -

$R_1$ is the radius of curvature of the first surface. -

$R_2$ is the radius of curvature of the second surface. Let's solve each of your questions: **Question 1:** Given

$n = 1.5$ ,

$R_1 = 15 \, \text{cm}$ , and

$R_2 = 20 \, \text{cm}$ , we need to calculate the difference in curvature between the two surfaces. Using the lens maker's formula, we can calculate the focal length, and then the difference in curvature. 1. Calculate

$\frac{1}{f}$ using the formula with the given values. 2. Once you find

$\frac{1}{f}$ , calculate the focal length

$f$ by taking the reciprocal. **Question 2:** Given

$n = 1.4$ and

$f = -12 \, \text{cm}$ , we need to determine the radii of curvature for the two lens surfaces. Using the lens maker's formula, you can calculate

$R_1$ and

$R_2$ . 1. Rearrange the lens maker's formula to solve for either

$R_1$ or

$R_2$ . 2. Plug in the known values and solve for

$R_1$ and

$R_2$ . **Question 3:** Given

$n = 1.6$ and

$f = 25 \, \text{cm}$ , we need to calculate the difference in radii of curvature for its two surfaces. Again, use the lens maker's formula to calculate

$R_1$ and

$R_2$ . **Question 4:** Given

$n = 1.2$ ,

$R_1 = 18 \, \text{cm}$ , and

$R_2 = \infty$ for a flat side, calculate the focal length using the lens maker's formula. **Question 5:** Given

$n = 1.6$ ,

$R_1 = 12 \, \text{cm}$ , and

$R_2 = 15 \, \text{cm}$ , calculate the focal length using the lens maker's formula. For each question, perform the calculations as described above, and you will have the answers you need. If you have any specific values to calculate or encounter any issues, feel free to ask for further assistance.

0Thank You

ANSWER

Classify industries on the basis of raw materials used. Explain each one of them with examples.

Posted by Khushi Kanwar 1 year, 6 months ago

CBSE > Class 12 > Geography

0 answers

ANSWER

Pen limit pen limited invited application for 75000 equity share of 100 is 20 on application 30 on allotment 20 on 1st call 30 on 2nd call application were received for 90000 equity share which were allotted on prorata basis A shareholder who applied for 1800 share fail to pay on first call and second

Posted by Badal Singh 1 year, 6 months ago

CBSE > Class 12 > Accountancy

0 answers

ANSWER

Wayne and tim are partner total interest on loan extended by wayne to firm is 20000 firm has net profit of 5000 the capital of wayne and tim are in the ratio of 2:3 what will be Wayne's share of profile or loss?

Posted by Mahi Singh 1 year, 6 months ago

CBSE > Class 12 > Accountancy

0 answers

ANSWER

State the meaning of commune

Posted by Suwashna Khokhar 1 year, 6 months ago

CBSE > Class 12 > Economics

0 answers

ANSWER

Explain any four factors that make European union a strong organisation

Posted by Aron Gurung 1 year, 6 months ago

CBSE > Class 12 > Political Science

1 answers

Kashish Gurawalia 1 year, 5 months ago

1. Common foreign and security policy 2. Corporation 3. Development and security 4. Creation common identity and flag

0Thank You

ANSWER

At wipro project

Posted by Muskan Nothing 1 year, 6 months ago

CBSE > Class 12 > Business Studies

1 answers

Account Deleted 1 year, 6 months ago

0Thank You

ANSWER

What is organic farming and advantages and disadvantages of organic farm

Posted by Kamal Buttar 1 year, 6 months ago

CBSE > Class 12 > Economics

0 answers

ANSWER

What is dry cell

Posted by Krushnakant Nayak 1 year, 6 months ago

CBSE > Class 12 > Chemistry

2 answers

Keshav Chauhan 1 year, 3 months ago

Dry cell is a primary cell. It works as voltaic cell. It is used in clocks, remotes,etc.

0Thank You

Aa Zz 1 year, 6 months ago

Which do not have liquid

1Thank You

ANSWER

3 marks 25 (a) In this painting three women are portrayed in the center of the picture plane with yellow, white and red saris, placed within the background of trees and nature. A dark black and brown portrayal of a woman behind the tree, seems to be in a resting mood also catches the eyes of the viewers. Identify and name the artist. (ii) Name the painting and the common spice depicted in it? (iii) Does the massive power of rural women reflect in the subject matter of the painting? Explain logically with your artistic point of view.

Posted by Yukti A 1 year, 6 months ago

CBSE > Class 12 > Painting

2 answers

Jiggu Jiggu 1 year, 4 months ago

Artist 1 Ans

0Thank You

Palak Sharma. 1 year, 5 months ago

2.Haldi grinder by Amrita shergill

1Thank You

ANSWER

How did the champaran peasants react when they here that a Mahatma had come to help them .

Posted by Riya Gupta 1 year, 6 months ago

CBSE > Class 12 > English Core

2 answers

Akash Pal 1 year, 6 months ago

How is everything

0Thank You

Akash Pal 1 year, 5 months ago

This content has been hidden. One or more users have flagged this content as inappropriate. Once content is flagged, it is hidden from users and is reviewed by myCBSEguide team against our Community Guidelines. If content is found in violation, the user posting this content will be banned for 30 days from using Homework help section. Suspended users will receive error while adding question or answer. Question comments have also been disabled. Read community guidelines at https://mycbseguide.com/community-guidelines.html

Few rules to keep homework help section safe, clean and informative.

Don't post personal information, mobile numbers and other details.
Don't use this platform for chatting, social networking and making friends. This platform is meant only for asking subject specific and study related questions.
Be nice and polite and avoid rude and abusive language. Avoid inappropriate language and attention, vulgar terms and anything sexually suggestive. Avoid harassment and bullying.
Ask specific question which are clear and concise.

Remember the goal of this website is to share knowledge and learn from each other. Ask questions and help others by answering questions.

0Thank You

ANSWER

To what extent were agricultural practices transformed in the period 600 BC to 600 AD

Posted by Sheetal Rana 1 year, 6 months ago

CBSE > Class 12 > History

1 answers

Sheetal Rana 1 year, 6 months ago

To what extent were agricultural practices transformed in the period 600 BC to 600 AD

0Thank You

ANSWER

The two lines X=ay+b, Z=cy+d and X = a'y+b' , Z=c'y+d' are perpendicular to each other , if (a) a/a' + c/c' = 1 (b) a/a' + c/c' = -1 (c) aa' + cc' = 1 (d) aa' + cc' = -1

Posted by Omkar Sachin Salunkhe. 1 year, 6 months ago

CBSE > Class 12 > Mathematics

1 answers

Ankush Thakur 1 year, 5 months ago

Don't post personal information, mobile numbers and other details.
Don't use this platform for chatting, social networking and making friends. This platform is meant only for asking subject specific and study related questions.
Be nice and polite and avoid rude and abusive language. Avoid inappropriate language and attention, vulgar terms and anything sexually suggestive. Avoid harassment and bullying.
Ask specific question which are clear and concise.

Remember the goal of this website is to share knowledge and learn from each other. Ask questions and help others by answering questions.

2Thank You

ANSWER

What is share holder fund

Posted by Sneha Nagar 1 year, 6 months ago

CBSE > Class 12 > Accountancy

0 answers

ANSWER

What are the various features of capital market?

Posted by Taufik Ansari 1 year, 6 months ago

CBSE > Class 12 > Business Studies

0 answers

ANSWER

Meera is a sprinter who participates in various competitions

Posted by Ruchi Gehlot 1 year, 6 months ago

CBSE > Class 12 > Physical Education

1 answers

Riya Saini 1 year, 6 months ago

What is mean by rickets

4Thank You

ANSWER

You are Karthika/Karthik of channai.of late, chain-snatching incidents are increasing in the city.write a letter to the editor of the New Indian express drawing the attention of the concerned authorities.also give suggestions.

Posted by Anusha Limboo 1 year, 6 months ago

CBSE > Class 12 > English Core

2 answers

Aditya Kumar Gupta 1 year, 5 months ago

Don't post personal information, mobile numbers and other details.
Don't use this platform for chatting, social networking and making friends. This platform is meant only for asking subject specific and study related questions.
Be nice and polite and avoid rude and abusive language. Avoid inappropriate language and attention, vulgar terms and anything sexually suggestive. Avoid harassment and bullying.
Ask specific question which are clear and concise.

Remember the goal of this website is to share knowledge and learn from each other. Ask questions and help others by answering questions.

0Thank You

Jannipalleruka.Prasanya Prasanya 1 year, 6 months ago

The Third level

2Thank You

ANSWER