कार्बन और इसके यौगिक - L6 | Previous Year Question Discussion |Class 10 विज्ञान | 8 AM | Nishtha Mam

Discussion OF Previous Years JEE Advanced Question 1-10

Class 10 Science - Most Important Topics | Previous Years Important Questions | CBSE Board 2020

When an object moves through a fluid, as when a ball falls through air or a glass sphere falls through water te fluid exerts a viscous foce F on the object this force tends to slow the object for a small sphere of radius r moving is given by stoke's law, F_(w)=6pietarv . in this formula eta in the coefficient of viscosity of the fluid which is the proportionality constant that determines how much tangential force is required to move a fluid layer at a constant speed v, when the layer has an area A and is located a perpendicular distance z from and immobile surface. the magnitude of the force is given by F=etaAv//z . For a viscous fluid to move from location 2 to location 1 along 2 must exceed that at location 1, poiseuilles's law given the volumes flow rate Q that results from such a pressure difference P_(2)-P_(1) . The flow rate of expressed by the formula Q=(piR^(4)(P_(2)-P_(1)))/(8etaL) poiseuille's law remains valid as long as the fluid flow is laminar. For a sfficiently high speed however the flow becomes turbulent flow is laminar as long as the reynolds number is less than approximately 2000. This number is given by the formula R_(e)=(2overline(v)rhoR)/(eta) In which overline(v) is the average speed rho is the density eta is the coefficient of viscosity of the fluid and R is the radius of the pipe. Take the density of water to be rho=1000kg//m^(3) Q. If the sphere in previous question has mass of 1xx10^(-5)kg what is its terminal velocity when falling through water? (eta=1xx10^(-3)Pa-s)

(i) In how many ways a committee of 4 members out of 5 gents and 6 ladies can be formed if there is at least one lady in the committee? (ii) From a class of 12 boys and 8 girls, 10 students are to be chosen for a competition, including at least 4 boys and 4 girls. The two boys whho won the prizes last year should be included. In how many was can this selection be made?

Thirty children were asked about the number of hours they watched TV programmes in the previous week. The results were found as follows: 1 6 2 3 5 12 5 8 4 8 10 3 4 12 2 8 15 1 17 6 3 2 8 5 9 6 8 7 14 12 (i) Make a grouped frequency distribution table for this data, taking class width 5 and one of the class intervals as 5 - 10. (ii) How many children watched television for 15 or more hours a week?

For recruiting Management Trainees in an organisation, thefollowingcriteriahavebeenlaiddown. The candidate must: (A) be a first class graduate in Commerce with at least 65% marks. (B) have secured at least 70% marks in SSC. (C) be not more than 26 years and not less than 21 years of age as on 1.8.2007. (D) have secured at least 60% marks in selection test. (E) have secured at least 50% marks in selection interview. However, if a candidate fulfils all the above mentioned criteria EXCEPT- (i) at (A) above but is an Economics graduate with at least 70% marks, the case may be referred to the GM of the organisation. (ii) at (E) above but has secured at least 40% marks in selection interview and at least70% marksin selection test, the case may be referred to the President of the organisation. In each of the questions below, information of one candidate is given. You have to take one of the following five dedsions based on the information provided and the criteria and conditions given above. You are not to assume any thing other than the information provided in each question. All these cases are given to you as on 1.08.2007. You have to indicate your dedsion by marking answers to each question as follows: Rakesh has passed SSC with 85% marks and graduation in Arts with specialisation in Economics with 72% marks. His date of birth is 12.6.1985. He has scored 65% marks in selection test as well as in interview.