In a photo electric experiment when a light of wavelength $$4000$$ Ao is used, stopping potential is found to be $$0.82$$ volt. Again when light of wave length $$3000$$ Ao is used stopping potential is found to be $$1.85$$ volt. Then find the value of plank's constant.

Question

In a photo electric experiment when a light of wavelength $$4000$$ Ao is used, stopping potential is found to be $$0.82$$ volt. Again when light of wave length $$3000$$ Ao is used stopping potential is found to be $$1.85$$ volt. Then find the value of plank's constant.

Infinity Learn · Accepted Answer

hcλ$$1=$$ϕ$$+eV1$$ and hcλ$$2=$$ϕ$$+eV2$$∴ hcλ$$2$$−hcλ$$1=e(V2$$−$$V1)$$⇒h×$$3$$×$$108(13$$×$$10$$−$$7$$−$$14$$×$$10$$−$$7)=1.6$$×$$10$$−$$19$$×(1.85$$−$$0.82)⇒h×$$3$$×$$10812$$×$$10$$−$$7=1.6$$×$$10$$−$$19$$×$$1.03$$⇒$$h=1.6$$×$$1.03$$×$$123$$×$$10$$−$$34J$$−$$S=6.592$$×$$10$$−$$34J$$−SAlternative solution :$$-$$ Just check the power.

In a photo electric experiment when a light of wavelength 4000 $\overset{o}{A}$ is used, stopping potential is found to be 0.82 volt. Again when light of wave length 3000 $\overset{o}{A}$ is used stopping potential is found to be 1.85 volt. Then find the value of plank's constant.

Remember concepts with our Masterclasses.

Ready to Test Your Skills?

free study material

In a photo electric experiment when a light of wavelength 4000 Ao is used, stopping potential is found to be 0.82 volt. Again when light of wave length 3000 Ao is used stopping potential is found to be 1.85 volt. Then find the value of plank's constant.

Remember concepts with our Masterclasses.

Ready to Test Your Skills?

free study material

In a photo electric experiment when a light of wavelength 4000 $\overset{o}{A}$ is used, stopping potential is found to be 0.82 volt. Again when light of wave length 3000 $\overset{o}{A}$ is used stopping potential is found to be 1.85 volt. Then find the value of plank's constant.