Tag: science & technology

The IEC 61158 Fieldbus standard (IEC 61158) currently includes 8 different communication network types. These include various industrial communication protocols like FOUNDATION Fieldbus, Profibus, and others that were standardized under this international standard. Options A (1), B (3), and D (15) are incorrect as they don't match the actual number of standardized networks.

Koneru Humpy became India's first Woman Grandmaster (WGM) in 2002 when she earned the title at age 15. Aarthie Ramaswamy and S. Vijayalakshmi are also strong chess players but Humpy achieved the WGM title first. S. Meenakshi is another Indian woman chess player but not the first WGM. The WGM title is the highest title for women chess players, below the unrestricted Grandmaster (GM) title.

Temperature is the most commonly measured variable in industrial process control and measurement. This is because temperature affects virtually every chemical reaction, physical process, and material property in industrial settings. Temperature sensors (thermocouples, RTDs, thermistors) are ubiquitous in process industries. While pressure, flow, and level are also critical measurements, temperature is measured more frequently than any other variable.

Infrared waves have longer wavelengths than visible red light. The visible spectrum ranges from approximately 380nm (violet) to 750nm (red). Infrared radiation starts just beyond red light (~700nm-1mm) and has longer wavelengths. Yellow and green have shorter wavelengths than red (~570-590nm for yellow, ~495-570nm for green), while ultraviolet has shorter wavelengths than the entire visible spectrum (~10-400nm).

The law of reflection states that the angle of incidence equals the angle of reflection. Both angles are measured with respect to the normal (a line perpendicular to the surface at the point of incidence). This is a fundamental principle of geometric optics and applies to all types of waves reflecting off surfaces. Options A and B are incorrect because the relationship is equality, not a fractional or multiple relationship.

A polarizer selectively transmits light waves oscillating in a specific direction while blocking others. When randomly polarized light (which contains waves vibrating in all directions perpendicular to propagation) passes through a linear polarizer, only the component aligned with the polarizer's transmission axis passes through. The emerging light becomes plane-polarized, meaning all waves vibrate in the same direction. It is not partially polarized (which implies some randomness remains), blocked (which would mean no transmission), or unchanged.

Light waves are transverse waves, meaning the oscillations of the electric and magnetic fields are perpendicular to the direction of wave propagation. Unlike longitudinal waves (like sound) where oscillations are parallel to propagation, light's transverse nature is why it can be polarized. Longitudinal waves cannot be polarized.

Light is an electromagnetic wave that can travel through vacuum without requiring any medium. Unlike mechanical waves such as sound, which need particles to propagate, light consists of oscillating electric and magnetic fields that are self-sustaining and can cross empty space.

The Sun is approximately 150 million kilometers from Earth, and light travels at about 300,000 km/s. This distance takes light roughly 8 minutes to cross, so if the Sun disappeared instantly, we would continue seeing it and feeling its gravity for 8 minutes - the information about its disappearance couldn't reach us faster than light speed.

Objects appear colored because they absorb some wavelengths of visible light and reflect others. Our eyes detect the reflected wavelengths. A red apple looks red because it absorbs most wavelengths and reflects red light. White objects reflect all wavelengths, while black objects absorb most visible light.