If `P` divides `O A` internally in the ratio `lambda_1:lambda_2` and `Q` divides `O A` externally in the ratio `lambda_1;lambda_2,` then prove that `O A` is the harmonic mean of `O P` and `O Qdot`

if mu_21 is 1.5, then find the value of lambda_1/lambda_2.

If the direction ratios of a line are 1 + lambda, 1- lambda, 2, and it makes an angle of 60^(@) with the y-axis then lambda is

The plane XOZ divides the join of (1, -1, 5) and (2, 3, 4) in the ratio of lambda:1 , then lambda is

If the line segment joining (2,3) and (-1,2) is divided internally in the ratio 3:4 by the line x+2y=lambda , then lambda =

If the points A(lambda, 2lambda), B(3lambda,3lambda) and C(3,1) are collinear, then lambda=

If xz-plane divide the join of point (2, 3, 4) and (1, -1, 5) in the ratio lambda:1 , then the integer lambda should be equal to

For sodium light, the two yellow ines occur at lambda_(1) and lambda_(2) wavelengths. If the mean of these two is 6000Å and |lambda_(2)-lambda_(1)|=6Å , then the approximate energy difference between the two levels corresponding to lambda_(1) and lambda_(2) is

If the direction ratios of a line are 1+lambda, 2-lambda, 4 and if it makes an angle of 60^(@) with the y- axis, then the sum of the values of lambda is

The largest integer lambda such that 2^(lambda) divides 3^(2^(n))-1, ninN is

Two mutually perpendicular wire carry charge densities lambda_1 and lambda_2 . The electric lines of force makes angle alpha with second wire, then lambda_1//lambda_2 is