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Suppose we have a simple discharge tube with two electrodes connected externally through ammeter and battery and evacuated internally.Now we shine radiation of suitable frequency on emmitter so that electrons are emmitted and photocurrent flows.Now my doubt, is the current flowing in external circuit measured by ammeter the same as that flows in the vacuum between the two electrodes due to photoelectric effect?Suppose 100 electrons are emitted per second from emitter plate.Will 100 electrons pass through any cross-sectional area in between the two electrodes and is the expression I=neAv valid for photocurrent?

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Yes. If everything is in series (ammeter, battery, discharge tube), then the current must be the same everywhere.

What are you wondering? Are you worried that the current in the tube is really low?

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  • $\begingroup$ I am thinking of a case when there is 0 voltage supply across tge tube then also current would flow.Suppose radiation caused 100 e- to be emmitted,of which 50 were lost or were of insufficient energy to reach collector plate, then only 50 e- would reach collector plate.So how in this case same current can be maintained $\endgroup$ – Sharad1 Jan 22 '20 at 10:57
  • $\begingroup$ Is your question really about stopping voltage? I'm not sure what you're asking... $\endgroup$ – Oscar Bravo Jan 22 '20 at 12:22
  • $\begingroup$ It is not about stopping potential.As mentioned in my previous comment consider of the case when there is no applied volatge. $\endgroup$ – Sharad1 Jan 22 '20 at 13:44
  • $\begingroup$ Try the duplicate question that is linked. $\endgroup$ – Oscar Bravo Jan 22 '20 at 14:47

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