Final answer:
Option b is correct option. A device that detects heat patterns in the infrared spectrum without direct contact is known as a thermal imager or thermograph, used for various applications from medical diagnostics to environmental and military surveillance.
Step-by-step explanation:
A device that detects heat patterns in the infrared-wavelength spectrum without making direct contact with equipment is known as a thermal imager or a thermograph. Thermography utilizes the principle that all objects emit infrared radiation proportional to the fourth power of their absolute temperature, allowing for the detection of subtle changes in heat. This makes it a powerful tool for applications ranging in scope from medical diagnostics, where it can reveal areas of high body temperature indicative of disease, to environmental and military surveillance, where it can detect individuals or objects by their infrared emissions.
The rate of heat transfer by radiation can vary significantly with temperature changes. For example, the percent increase in the rate of heat transfer by radiation from an area at a temperature of 34.0°C compared with 33.0°C, such as on human skin, would be dictated by the T4 dependence outlined in the Stefan-Boltzmann law. Similarly, comparing an area at 34.0°C with an area at 20.0°C, such as different parts of an automobile hood, would show a more substantial percentage increase due to the same law.