Assertion: A photocell is called an electric eye.
Reason: When light is incident on some semiconductor its electrical resistance is reduced

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Both assertion and reason are correct and reason is the correct explanation of assertion

Both assertion and reason are correct but reason is not the correct explanation of assertion

Assertion is correct but reason is incorrect

Both assertion and reason are incorrect

answer is B.

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Detailed Solution

Concept: A variety of photocells are made to respond to different frequencies of electromagnetic waves, such as x-rays, visible light, and so on.
The electron will consume a portion of the radiation's energy when it strikes the cathode, a process known as the work function, and the remainder will be used as kinetic energy to go to the anode. Current is created automatically when an electron reaches the anode. Consequently, light is employed in photocells to produce energy. The radiation's intensity affects how much current is generated.
Now, if the cathode and anode potential difference is maintained and a photocell is used in the dark, no electricity is produced since no electrons are at all released from the electrode. Therefore, we claim that when light is incident on it, its resistance decreases. To deter robberies, they are employed as electrical alarms. When a robber shines a light on the cash throughout the night, photo cells in the bank detect that light and instantly sound an alert or siren. This is why they are referred to as an electrical eye. Since the light's intensity determines the current flow that triggers the alarm, the claim and reason are both true, but reason is not the proper explanation.
Hence, the correct Option is 2.

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