Which of the following statement is not correct

Options

A. Photographic plates are sensitive to infrared rays
B. Photographic plates are sensitive to ultraviolet rays
C. Infra-red 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, we will analyze each statement one by one.

### Step 1: Analyze the first statement
**Statement:** Photographic plates are sensitive to infrared rays.
**Analysis:** Photographic plates are indeed sensitive to infrared rays. This statement is correct.

### Step 2: Analyze the second statement
**Statement:** Photographic plates are sensitive to ultraviolet rays.
**Analysis:** Photographic plates are also sensitive to ultraviolet rays. This statement is correct.

### Step 3: Analyze the third statement
**Statement:** Infrared rays are invisible but can cast shadows like visible light.
**Analysis:** Infrared rays are indeed invisible to the human eye, but they can cast shadows similar to visible light. This statement is correct.

### Step 4: Analyze the fourth statement
**Statement:** Infrared photons have more energy than photons of visible light.
**Analysis:** To compare the energy of infrared photons and visible light photons, we need to consider their wavelengths. Infrared rays have longer wavelengths than visible light, and energy is inversely related to wavelength (E = h * c / λ). Therefore, infrared photons have less energy than visible light photons. This statement is incorrect.

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

---