Light from a hydrogen discharge tube is incident on the cathode of a photocell. The work function of cathode surface is 4.2 eV.In order to reduce the photocurrent to zero, the voltage of the anode relative to the cathode must be made :

Light from a hydrogen discharge tube is incident on the cathode of a p

1.	Light from a hydrogen discharge tube is incident on the cathode of a photocell. The work function of cathode surface is 4.2 eV.In order to reduce the photocurrent to zero, the voltage of the anode relative to the cathode must be made :
Answer» `-4.2 V` `-9.4 V` `-17.8 V` `+9.4 V` ANSWER :B

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Light from a hydrogen discharge tube is incident on the cathode of a photocell. The work function of cathode surface is 4.2 eV.In order to reduce the photocurrent to zero, the voltage of the anode relative to the cathode must be made :

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