Ask questions, doubts, problems and we will help you..
Ask questions which are clear, concise and easy to understand.
Ask Question
CBSE, JEE, NEET, CUET
Question Bank, Mock Tests, Exam Papers
NCERT Solutions, Sample Papers, Notes, Videos
Posted by Punya Thukral 5 years ago (9979833)
- 3 answers
Anurag Sathe 5 years ago (10360722)
Posted by Arpita Nehra 5 years ago (10379274)
- 0 answers
Posted by Vedant Bhosle 5 years ago (9662740)
- 4 answers
Ridhima Sharma 4 years, 11 months ago (10507343)
[email protected] Hav 4 years, 11 months ago (8965903)
Posted by Preethi Harish 5 years ago (10375547)
- 3 answers
Posted by Rohit Rawat 5 years ago (10402485)
- 0 answers
Posted by Abhinav Kumar Singh 5 years ago (10402616)
- 0 answers
Posted by Rishu Kumar 5 years ago (10169092)
- 2 answers
Posted by Sugam Bindal 5 years ago (7397600)
- 0 answers
Posted by Aslam Khan 5 years ago (9857734)
- 2 answers
Posted by Simranjit Kaur Cheema 5 years ago (5734386)
- 0 answers
Posted by Diksha Laniya 5 years ago (10402180)
- 0 answers
Posted by Priyanka Mohan 5 years ago (10373085)
- 0 answers
Posted by Jyotshna Priya 5 years ago (9955428)
- 1 answers
Posted by Rachel Varghese 5 years ago (9586543)
- 0 answers
Posted by Akriti Kumari 5 years ago (10316988)
- 2 answers
Aditi Sharma 4 years, 10 months ago (10483992)
Posted by Akriti Kumari 5 years ago (10316988)
- 1 answers
Posted by Suba Ragav 5 years ago (9479168)
- 1 answers
Shruti ? 5 years ago (9554162)
Posted by Ankit Kumar 5 years ago (5775411)
- 1 answers
Utkarsh Gupta 5 years ago (5179761)
Posted by Krishna Soni 5 years ago (3765486)
- 1 answers
Manish Jee 5 years ago (8908542)
Posted by Rishika Chowdhary 5 years ago (10304226)
- 0 answers
Posted by Kunal Singh Thakur 5 years ago (10508567)
- 2 answers
Posted by @Yush Sharma 5 years ago (10078141)
- 0 answers
Posted by Aachal Satwan 4 years, 7 months ago (9499811)
- 1 answers
Sia ? 4 years, 7 months ago (6945213)
Magnification = Image distance / Object distance
In this case :
Let the magnification in the first case be x.
The magnification in the second case will be 3x.
The mirror formula is :
1/u + 1/v = 1/f
The first case
Magnification = x
Object distance = 25 cm
Image distance = Object distance × Magnification
= 15x cm
Now :
1/15 + 1/15 x = 1/f
Lcm = 15x
Solving we have :
(1 + x)/15x = 1/f
f = 15x/(1 + x)
Second case
Object distance = 9 cm
magnification = 3x
Image distance = 27x cm
1/9 + 1/27x = 1/f
Lcm = 27x
(3x + 1)/27x = 1/f
f = 27x/(3x + 1)
Since we have two values of f we can equate them as follows:
27x/(3x + 1) = 15x/(x + 1)
Solving for x we have :
27x(x + 1) = 15x(3x + 1)
27x² + 27x = 45x² + 15x
Collecting like terms together
45x² - 27x² = 27x - 15x
18x² = 12x
Divide through by x
18x = 12
x = 12/18
x = 2/3
Substitute to get f:
f = (27 × 2/3)/(3 × 2/3 + 1)
f = 18/3
= 6 cm
Posted by Mahi Kashyap 5 years ago (9597758)
- 2 answers
Posted by Yash Dhingra 5 years ago (9519916)
- 5 answers
Posted by Aditi Das 5 years ago (10400092)
- 4 answers
Itika And Shubh Bajpai 4 years, 11 months ago (10288110)
Posted by Faizan Sheikh 5 years ago (10199118)
- 1 answers
Shivani Narwar 5 years ago (10049163)
Posted by Rahul Kumar 5 years ago (10354846)
- 1 answers
Aishvaryam Yash 5 years ago (6998000)
Posted by Hasina Mandar 5 years ago (10209167)
- 2 answers
Nitya Gupta 5 years ago (9253892)
Nitya Gupta 5 years ago (9253892)
Posted by Tiger ? 5 years ago (10401747)
- 1 answers
Himanshi Sahu 5 years ago (9968525)
myCBSEguide
Trusted by 1 Crore+ Students
Test Generator
Create papers online. It's FREE.
CUET Mock Tests
75,000+ questions to practice only on myCBSEguide app
Disha S 5 years ago (4392449)
1 Thank You