सूक्ष्मजीव : मित्र एवं प्रबंध | Class 8 विज्ञान | 7 PM Class by Amba Ma'am | L1 | Hindi Medium

12 PM Special Class | Class 11 - STRUCTURE OF ATOM || BOHR MODEL By Yakshu Ma'am

A person from A starts to walk at 7 am and reaches B at 1 pm and another person starts to walk from B at 8 am and reaches A at 11 am. Find the time at which they meet each other.

Ratio of the fares of First ,Second and Third class catogory of a train , between two stations is 10:7:2 and the ratio of passenger travelling in these category is 4:9:17 respectively .If the fare is increased by 1/4 in First class , 1/8 in second class and decreased by 10% i Third Class and the ratio of number of passenger in the category remains same .If the total amount received of Rs. 60590 , then find the total amount received from thrid class category .

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?

Each of the questions below consists of a question and two statements numbered I and II given below it. You have to decide whether the data provided in the statements are sufficient to answer the question. Read both the statements and give answer 1) if the data in statement I alone are sufficient to answer the question while the data in statement II alone are not sufficient to answer the question. 2) if the data in statement II alone are sufficient to answer the question while the data in statement I alone are not sufficient to answer the question. 3) if the data either in statement I alone or in statement II alone are sufficient to answer the question. 4) if the data even in both statements I and II together are not sufficient to answer the question. 5) if the data in both statements I and II together are necessary to answer the question. What is Kumud’s rank in a class of 40? I. Seema, who is 8th from the top in the class, is above Kailash by 18 ranks, who is below Kumud by 7 ranks. II. Nandini, who is between Kumud and Kishori, is 20th from the bottom.

KMnO_4 is prepared from the mineral pyrolusite, MnO_2 (deep purple colour). It acts as an oxidising agent in the neutral, alkaline as well as acidic medium in acidic medium it is used in volumetric analysis for estimation of Fe^(2+) , Cr_2O_4^(2-) salts etc. The titrations are carried out in presence of H_2SO_4 . However, before using it as a titrant, it is first standardised with standard oxalic acid solution or Mohr's salt solution . In one of the experiments on titration 26.8g of dry pure sodium oxalate (Mw=123gmol^-1) was dissolved in 1L of distilled water and then 100 mL of 2MH_2SO_4 were added. The solution was cooled. Now to this solution 0.1MKMnO_4 solution was added till a very faint pink colour persisted. Q. If 0.1MK_2Cr_2O_7 solution were used in place of 0.1 MKMnO_4 solution used would be

KMnO_4 is prepared from the mineral pyrolusite, MnO_2 (deep purple colour). It acts as an oxidising agent in the neutral, alkaline as well as acidic medium in acidic medium it is used in volumetric analysis for estimation of Fe^(2+) , Cr_2O_4^(2-) salts etc. The titrations are carried out in presence of H_2SO_4 . However, before using it as a titrant, it is first standardised with standard oxalic acid solution or Mohr's salt solution . In one of the experiments on titration 26.8g of dry pure sodium oxalate (Mw=123gmol^-1) was dissolved in 1L of distilled water and then 100 mL of 2MH_2SO_4 were added. The solution was cooled. Now to this solution 0.1MKMnO_4 solution was added till a very faint pink colour persisted. Q. Mohr's salt, FeSO_4(NH_4)_2SO_46H_2O , is preffered over FeSO_4.7H_2O for standardisation of KMnO_4 solution because.