Em Spectrum - Infrared

Explanation
Near infrared is not emitted by the sun. The sun primarily emits visible light, ultraviolet light, and a small amount of infrared radiation. Near infrared radiation is actually a type of electromagnetic radiation that is emitted by objects that are warm, such as the human body or certain types of technology.

Explanation
Far infrared refers to a specific range of electromagnetic radiation with longer wavelengths than visible light. This type of radiation is known to have thermal properties, meaning it can generate heat when absorbed by an object. Therefore, the statement "Far infrared are thermal" is true, as far infrared radiation is indeed thermal in nature.

Explanation
Near infrared is indeed used in remote controls such as television. Remote controls use infrared light to transmit signals to the device being controlled. This is because infrared light is not visible to the human eye, making it ideal for remote control applications. When a button is pressed on the remote control, it emits a signal in the form of infrared light pulses. The device being controlled, such as a television, has a receiver that detects these pulses and interprets them as commands. Therefore, the correct answer is true.

Explanation
Infrared does not increase visibility in the dark. This statement is false because infrared light is not visible to the human eye, but it can be detected by certain devices such as night vision goggles or cameras. These devices can convert the infrared light into visible light, allowing us to see in the dark. Therefore, infrared technology can actually enhance visibility in low light or dark conditions.

Explanation
Missiles, heat seekers, track down their target by detecting the infrared emission. Infrared radiation is emitted by objects due to their heat. Heat seekers are equipped with infrared sensors that can detect the infrared radiation emitted by the target. The sensors on the missile can differentiate between the heat emitted by the target and the surrounding environment, allowing the missile to lock onto the target and track it accurately. This technology is commonly used in military applications to guide missiles towards their intended targets.