Question #f486d

1 Answer
Jan 31, 2016

#9/5#

Explanation:

we know,
the equation of wavelength of spectrum is,

#1/lambda=R_H(1/n_1^2-1/n_2^2)#

#or, lambda=(n_1n_2)/(n_2^2-n_1^2)#

for the first line of pashchen series the equation becomes,

#lambda_1=(1*3)/(3^2-1^2)#

#=3/(9-1)#

#=3/8#

for the first line of pfund series the equation becomes,

#lambda_2=(1*5)/(5^2-1^2)#

#=5/(25-1)#

#=5/24#

so,

#lambda_1/lambda_2=(3/8)/(5/24)=3/8xx24/5=9/5#