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Assertion : Potassium and caesium are us...

Assertion : Potassium and caesium are useful as electrodes in photoelectric cells.
Reason : Potassium and caesium, when irradiated with light, the light energy absorbed is sufficient to eject out the electron from a atom.

A

If both (A) and (R) are correct and (R) is the correct explanation of (A).

B

If both (A) and (R) are correct, but (R) is not the correct explanation of (A).

C

If (A) is correct, but (R) is incorrect.

D

If both (A) and (R) are incorrect.

Text Solution

Verified by Experts

The correct Answer is:
A
Low ionisation energies of potassium and caesium.
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Knowledge Check

  • Statement 1 : Potassium and caesium are useful as electrodes in photoelectric cells. Statement 2 : Potassium and caesium, when irradiated with light, the light energy absorbed is sufficient to eject out the electron from a atom.

    A
    Statement 1 is True, statement 2 is True , Statement 2 is Correct explanation for Statement 1.
    B
    Statement 1 is True, Statement 2 is True , Statement 2 is NOT a correct explanation for Statement 1.
    C
    Statement 1 is True, Statement 2 is False
    D
    Statement 1 is False, Statement 2 is True.

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    A
    If both Assertion and Reason are true and Reason is the correct explanation of Assertion
    B
    If both Assertion and Reason are true but Reason is not correct explanation of Assertion
    C
    If Assertion is true but Reason is false.
    D
    If both Assertion and Reason are false

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    If both Assertion and Reason are true and Reason is the correct explanation of Assertion
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    C
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    D
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