ધોરણ 8 વિજ્ઞાન સ્વ અધ્યયન પોથી 10 ,dhoran 8 vigyan swadhyay pothi , std 8 vigyan svadhyaypothi sem 2

The negation of the statement 2+3=5 and 8<10 is-

Variance of the data 2,4,6,8,10 is

Variance of the data 2,4,6,8,10 is

2x + y ge 8, x + 2y ge 10

Four charges 10^(-8), -2 xx 10^(8), +3xx10^(-8) and 2xx10^(-8) coulomb are placed at the four corners of a square of side 1m the potential at the centre of the square is

Find the center and radius of the circle x^2+y^2+8x+10y-8=0 .

Four companies submitted the quotations for building a bridge, with the following values of breaking stress (B_(s)) and working stress (W_(s)) expressed in N//m^(2) (A) B_(s) = 25 xx 10^(8), W_(s) = 15 xx 10^(8) (B) B_(s) = 20 xx 10^(8), W_(s) = 15 xx 10^(8) (C ) B_(s) = 25 xx 10^(8), W_(s) = 12.5 xx 10^(8) (D) B_(s) = 25 xx 10^(8), W_(s) = 20 xx 10^(8) To whome the contract should be given, if all of them have quoted the same amount ?

The average lifetime for the n = 3 excited state of a hydrogen-like atom is 4.8 xx 10^(-8) s and that for the n = 2 state is 12.8 xx 10^(-8) s . The ratio of average number of revolution made in the n = 3 sate before any transition can take place from these state is.

Assertion : Consider the marks scored by 10 students in a test. 10, 9, 9, 8, 2, 8, 2, 8, 8, 7. The frequency of 8 in the data is 4. Reason : 8 occurs 4 times in the data. So, its frequency is 4.

In a Std. X class, out of 40 students, 10 students use spectacles, 2 students have positive power and 8 students have negative power and 8 students have negative power of lenses in their spectacles . What does the positive power indicate ?