Figuresk8r89 If you see this question please talk to me please

What should the power status of a circuit be when measuring resistance with an ohmmeter?

Light from a sodium lamp passes through a diffraction grating that has 1000 slits per millimeter. the interference pattern is viewed on a screen 1.000 m behind the grating. the first (m = 1) two bright yellow fringes that are visible are 0.7288 m and 0.7300 m from the central maximum. what are the wavelengths of these two fringes?

Avoltaic cell converts chemical energy to