7 NUMBER पक्के ✅ विद्युत मोटर तथा विद्युत जनित्र | ELECTRIC MOTOR AND GENERATOR | CLASS 10 PHYSICS

चुंबक तथा चुम्बकत्व|चुंबकीय क्षेत्र रेखाएँ तथा गुण|ऑरेसटेड का प्रयोग|सीधी धारावाही चालक तार में चुंबकीय क्षेत्र |दाहिने हाथ के अंगूठे का नियम|परिनालिका|विद्युत चुंबक|धारावाही चालक पर लगने वाला बल|फ्लेमिंग का वाम हस्त नियम|विद्युत मोटर के मुख्य भाग|वैद्युत

The average weight of a certain number of students in a class is 68.5 kg. If 4 new students having weights 72.2 kg, 70.8kg, 70.3kg and 66.7 kg join the class, then the average weight of all the students increases by 300 g. The number of students in the class, initially is: किसी कक्षा में छात्रों की एक निश्चित संख्या का औसत वज़न 68.5 किलो ग्राम है | यदि 4 नए छात्र कक्षा में आ जाते हैं, जिनका वज़न क्रमशः 72.2 किलो ग्राम, 70.8 किलो ग्राम, 70.3 किलो ग्राम तथा 66.7 किलो ग्राम है, तो सभी छात्रों का औसत वज़न 300 ग्राम से बढ़ जाता है | आरंभ में कक्षामें छात्रों की संख्या कितनी थी ?

The number of students in classes A and B are 60 and 70, respectively. The average score in mathematics of students in B is 57 and that of all students in A and B is 63. What is the average score of students in A? कक्षा A और B में छात्रों की संख्या क्रमश: 60 और 10 है | B में गणित में छात्रों का औसत अंक 57 तथा A और B के सभी छात्रों का गणित में औसत अंक 63 है |A के छात्रों का औसत अंक ज्ञात करें |

The average of 20 numbers is 80. The average of first 10 numbers is 76.5 and that of next 7 numbers is 82. The 18th number is 3 more than the 19th number but 3 less than the 20th number. What is the average of 18th and 19th numbers? 20 संख्याओं का औसत 80 है | पहली 10 संख्याओं का औसत 76.5 है तथा अगली 7 संख्याओं का औसत 82 है | 18वीं संख्या 19वीं संख्या से 3 अधिक है लेकिन 20वीं संख्या से 3 कम है | 18वीं तथा 19वीं संख्या का औसत ज्ञात करें |

The average of 24 numbers is 56. The average of the first 10 numbers is 71.7 and that of the next 11 numbers is 42. The next three numbers (i.e 22nd ,23rd and 24th) are in the ratio 1/2 : 1/3: 5/12 . What is the average of the 22nd and 24th numbers? 24 संख्याओं का औसत 56 है | पहली 10 संख्याओं का औसत 71.7 है तथा अगली 11 संख्याओं का औसत 42 है| अगली तीन संख्याएँ ( अर्थात 22वीं, 23वीं तथा 24वीं ) 1/2 : 1/3: 5/12 के अनुपात में हैं | 22वीं तथा 24वीं संख्याओं का औसत कितना है ?

In a slow reaction, heat is being evolved at a rate about 10 m W in a liquid. If the heat were being generated by the decay of ^(32) P, a radioactive isotope of phosphorus that has half-life of 14 days and emits only beta-particles with a mean energy of 700KeV, estimate the number of ^(32) P atoms in the liquid. Express your answer in form of Axx10^(15) and fill A in OMR sheet. Round off A to nearest integer [Take:l n 2=0.7 ]

In a class 20 students read mathematics, 16 read physics and 10 read both the subjects. The number of students in the class who read either mathematics or physics is (A) 20 (B) 16 (C) 10 (n) 26

(Questions 10-14): Study the following pie-chart and the table given below it carefully to answer the questions given below: Percentage-wise distribution of lecturers in 6 different subjects in a university total number of lecturers: 1600 (FIGURE) Ratio of male to female lecturers Lecturers Males : Females Mathematics 3 : 4 Education 5 : 3 Hindi 1 : 3 Chemistry 1 : 7 Physics 9 : 5 Zoology 7 : 9 Total number of lecturers (both male and female) in Hindi is approximately what per cent of the total number of female lecturers in Mathematics and Chemistry together? (a) 58 (b) 43 (c) 47 (d) 51 (e) 50

The number of students absent in a class were recorded every day for 120 days and the information is given in the following frequency table: No. of students absent (x) : 0 1 2 3 4 5 6 7 No. of days (f) : 1 4 10 50 34 15 4 2 Find the mean number of students absent per day.