प्रत्यास्थता गुणांक | ठोसों के यांत्रिक गुण | 11th Physics | Chapter 9 | Part 02 | By Gopal Sir

Class 12 Physics | Chapter 9 Ray Optics and Optical Instruments | Important Questions & Quick Revision | Part 1

Class 12 Physics | Chapter 9 Ray Optics and Optical Instruments | Important Questions & Quick Revision | Part 2

Class 12 Physics | Chapter 9 Ray Optics and Optical Instruments | Important Questions & Quick Revision | Part 3

The average of eleven numbers is 54. The average of the first four numbers is 48 and that of the next four numbers is 25% more than the average of the first four. The ninth number is 8 greater than the 11th number and the tenth number is 4 greater than the 11th number. What is the average of the 9th and the 10th numbers? 11 संख्याओं का औसत 54 है | पहली चार संख्याओं का औसत 48 है तथा अगली चार संख्याओं का औसत पहली चार संख्याओं के औसत से 25% अधिक है | 9वीं संख्या 11वीं संख्या से 8 अधिक है तथा दसवीं संख्या 11वीं संख्या से 4 अधिक है | 9वीं और 10वीं संख्याओं का औसत ज्ञात करें |

The ratio of the efficiencies of A, B and C is 2 : 5 : 3. Working together, they can complete a work in 27 days. B and C together can complete 4/9th part of that work in: A, B और C की कार्य क्षमता का अनुपात 2 : 5 : 3 है | एक साथ कार्य करते हुए, वे किसी कार्य को 27 दिन में पूरा कर सकते हैं | B और C एक साथ उस कार्य के 4/9 भाग को कितने दिनों में पूरा करेंगे ?

A 1m long rod having uniform area of cross section is made of four materials. The first 0.2 m is made of iron, the next 0.3m of lead, the following 0.2m of aluminium and the remaining part is made of copper. Find the centre of mass of the rod. The densities of iron, lead, aluminium and copper are 7.9xx10^3 kg//m^3,11.4xx10^3 kg//m^3, 2.7 xx 10^3 kg//m^3 "and" 8.9 xx 10^3kg//^3 respectively.