Home
Class 12
PHYSICS
The cathode of a photoelectric cell is c...

The cathode of a photoelectric cell is changed such that the work function changes from `(W_(1) to W_(2) (W_(2) gt W_(1))`. If the current before and after change are `I_(1)` and `I_(2)`, all other conditions remaining unchanged , then (assuming `hv gt W_(2)`)

A

`I_(1)` = `I_(2)`

B

`I_(1) lt I_(2)`

C

`I_(1) gt I_(2)`

D

`I_(1) lt I_(2) lt 2I_(1)`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze how the change in work function affects the current in a photoelectric cell while keeping other conditions constant. ### Step-by-Step Solution: 1. **Understanding Work Function**: The work function (W) is the minimum energy required to remove an electron from the surface of a material. In this case, we have two work functions: W1 (before the change) and W2 (after the change), with W2 > W1. 2. **Photoelectric Effect Condition**: The condition given is that the energy of the incident photons (hv) is greater than W2. This means that the photons have enough energy to emit electrons from the cathode even after the work function has increased. 3. **Current in the Photoelectric Cell**: The current (I) in a photoelectric cell is directly proportional to the number of electrons emitted from the cathode. The number of emitted electrons depends on the intensity of the incident light, not on the work function or frequency, as long as the energy of the photons is sufficient to overcome the work function. 4. **Intensity and Current Relationship**: Since the intensity of the incident light is unchanged in this scenario, the number of emitted electrons remains constant. Therefore, the current before the change (I1) and after the change (I2) will be the same. 5. **Conclusion**: Since all other conditions remain unchanged and the intensity is constant, we conclude that: \[ I_1 = I_2 \] ### Final Answer: Thus, the current before and after the change in work function will be equal: \[ I_1 = I_2 \]
Promotional Banner

Similar Questions

Explore conceptually related problems

The weight of an object in the coal mine, sea level and at the top of the mountain are W_(1),W_(2) and W_(3) respectively, then

Ultraviolet light is incident on two photosensitive materials having work function W_(1) and W_(2) (W_(1) gt W_(2)) . In which case will the kintic enrgy of the emitted electrons be greater? Why?

A gas is expanded to double its volume by two different processes. One is isobaric and the other is isothermal. Let W_(1) and W_(2) be the respective work done, then find W_(1) and W_(2)

In the accompanying diagram W_(1) is 5kg weight and W_(2) is 3 kg weight. If the component of W_(1) parallel to the incline is equal to W_(2) , then the angle theta is nearly :

Two weights W_(1) and W_(2) in equilibrium and at rest, are suspended as shown in figure. Then the ratio (W_(1))/(W_(2)) is :

A body of weight w_(1) when floats in water displaces an amount of water w_(2) . Then w_(1)ltw_(2) . In this statement true or false?

If i_(1)=3 sin omega t and (i_2) = 4 cos omega t, then (i_3) is

W_(1),W_(2) and W_(3) are the different sizes of windows 1, 2, and 3 respectively placed in a vertical plane. A particle is thrown up in the vertical plane. Let t_(1),t_(2) and t_(3) are the time taken to cross the window W_(1), W_(2) and W_(3) respectively and DeltaV_(1), DeltaV_(2) and DeltaV_(3) are the change in speed after respective window cross.

Plot a graph showing the variation of stopping potential with the frequency of incident radiation for two different photosensitive having work functions W_1 and W_2(W_1 gt W_2) . On what factors does the (i) slope and (ii) intercept of the lines depend ?

A given mass of a gas expands from the state A to the state B by three paths 1,2 and 3 as shown in the figure, If W_(1),W_(2) and W_(3) respectively be the work done by the gas along the three paths then