A grating is to be used to find the wavelength of the emission ...

[WWatsford]

A grating is to be used to find the wavelength of the emission spectrum of a gas. The grating spacing is not known,
 
  but light of a known wavelength of 632.8 nm is deflected by 43.2 in the second order by this grating. Light of the wavelength to be measured is deflected by 34.9 in the second order. What is the wavelength of the light that is to be measured?

Question 2

An instrument is rated at 250 W if it is connected across a 120-V dc power supply.
 
  (a) What current does it draw under normal operation?
  (b) What is its resistance?
  (c) How many kilowatt-hours does it use in a day if it is left on all the time?

[ultraflyy23]

Answer to Question 1

529 nm

Answer to Question 2

(a) 2.1 A (b) 58  (c) 6.0 kWh

[WWatsford]

Thanks for the timely response, appreciate it

[sultansheikh]

Wow, this really help