Which of the following statements is not correct ?

Options

A. Photographic plates are sensitive to infrared rays
B. Photographic plates are sensitive to ultraviolet rays
C. Infrared rays are invisible but can cast shadows like visible light
D. Infrared photons have more energy than photons of visible light

Answer

To determine which statement is not correct, let's analyze each option step by step.

### Step 1: Analyze Statement A
**Statement A:** Photographic plates are sensitive to infrared rays.

- Photographic plates are indeed sensitive to infrared rays. They can capture images in the infrared spectrum, which is beyond the visible range.

**Conclusion:** This statement is correct.

### Step 2: Analyze Statement B
**Statement B:** Photographic plates are sensitive to ultraviolet rays.

- Similar to infrared rays, photographic plates are also sensitive to ultraviolet rays. They can capture images in the ultraviolet spectrum as well.

**Conclusion:** This statement is correct.

### Step 3: Analyze Statement C
**Statement C:** Infrared rays are invisible but can cast shadows like visible light.

- Infrared rays are indeed invisible to the human eye, but they can still cast shadows. The ability to cast shadows depends on the light source and not on the visibility of the light.

**Conclusion:** This statement is correct.

### Step 4: Analyze Statement D
**Statement D:** Infrared photons have more energy than photons of visible light.

- This statement is incorrect. The energy of a photon is directly proportional to its frequency (E = hν). Infrared photons have a lower frequency than visible light photons, which means they have less energy.

**Conclusion:** This statement is incorrect.

### Final Conclusion
The statement that is not correct is **Statement D:** "Infrared photons have more energy than photons of visible light."

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