​​Why do Fruits float in Water?

​​Why do Fruits float in Water?

Because the peel is designed to protect the inside of the orange, its structure is different. Besides being tougher than the sweet interior, the peel also contains a lot of air. The peel is less dense than water or light enough to float, but the inside Fruit is denser than Water so it sinks.

Different Fruits and Vegetables will also float or sink depending on their density. In general, apples, bananas, lemons, oranges, pears, and zucchinis will float, while avocados, potatoes, and mangoes will sink. Others like turnips and sweet potatoes sometimes sink and sometimes float.

​​Why we put Salt and Charcoal into Earth-pit while Earthing?

​​Why we put Salt and Charcoal into Earth-pit while Earthing?

Earthing resistance is not the resistance of the electrode. The earthing resistance is not same all over the area. The value of earting resistance is depends upon the soil resistivity of the particular area. Actually the measured earth resistance is not only the resistance of the electrode, it is the combined resistance of conductor and the associated soil. During fault, if the soil resistance is higher the fault current cannot dissipate to associate soil.

To improve the conductivity of poor soil during fault current, salt and charcoal around the conductor is used to dissipate. 

Charcoal is used to retain the moisture for long duration because it is an adsorbent and salt is added to increase the conductivity both these products help to pass the leakage current through earth wire as early as possible to remove the chances of shock.

We can practice permanent earthing compounds which are moisture independent as per IEEE 80–2013 clause 14.5(d).

​​How does Stealth technology work?

​​How does Stealth technology work?

The goal of stealth technology is to make an airplane invisible to radar. There are two different ways to create invisibility:

The airplane can be shaped so that any radar signals it reflects are reflected away from the radar equipment.

The airplane can be covered in materials that absorb radar signals.

Most conventional aircraft have a rounded shape. This shape makes them aerodynamic, but it also creates a very efficient radar reflector. The round shape means that no matter where the radar signal hits the plane, some of the signal gets reflected back:

A stealth aircraft, on the other hand, is made up of completely flat surfaces and very sharp edges. When a radar signal hits a stealth plane, the signal reflects away at an angle. 

In addition, surfaces on a stealth aircraft can be treated so they absorb radar energy as well. The overall result is that a stealth aircraft like an F-117A can have the radar signature of a small bird rather than an airplane. The only exception is when the plane banks -- there will often be a moment when one of the panels of the plane will perfectly reflect a burst of radar energy back to the antenna.

​​Why is Spotted Lake spotted?

​​Why is Spotted Lake spotted?

Spotted Lake is a small lake rich in a variety of Minerals, including Calcium, Sodium sulphates and Magnesium sulphate. During the hot summer months, much of the water in the lake evaporates, leaving concentrations of these minerals that form the spots visible in the lake. Spotted Lake was for centuries and remains revered as a sacred site thought to provide therapeutic waters. It is also known as Kliluk Lake.

​​What is the difference between ‘Cemetery’ and ‘Graveyard’?

​​What is the difference between ‘Cemetery’ and ‘Graveyard’?

From about the 7th century C.E., the process of burial was firmly in the hands of the Church (the Christian organization), and burying the dead was only allowed on the lands near a church (now referring to the building), the so-called churchyard. The part of the churchyard used for burial was called graveyard.

As the population of Europe started to grow, the capacity of graveyards was no longer sufficient (the population of modern Europe is almost 40 times higher than it was in the 7th century). By the end of the 18th century, the unsustainability of church burials became apparent, and completely new places for burying people, independent of graveyards, appeared—and these were called cemeteries.

​​What is Wearable Technology?

​​What is Wearable Technology?

Wearable technology, wearables, fashion technology, tech togs, or fashion electronics are smart electronic devices (electronic device with micro-controllers) that are worn close to and/or on the surface of the skin, where they detect, analyze, and transmit information concerning e.g. body signals such as vital signs, and/or ambient data and which allow in some cases immediate biofeedback to the wearer.

Wearable devices such as activity trackers are an example of the Internet of Things, since "things" such as electronics, software, sensors, and connectivity are effectors that enable objects to exchange data (including data quality) through the internet with a manufacturer, operator, and/or other connected devices, without requiring human intervention.

Wearable technology has a variety of applications which grows as the field itself expands. It appears prominently in consumer electronics with the popularization of the Smart Watch and activity tracker. Apart from commercial uses, wearable technology is being incorporated into navigation systems, advanced textiles, and healthcare.

​​How does Smoke Detector Alarm work?

​​How does Smoke Detector Alarm work?

The two most commonly recognized smoke detection technologies are ionization smoke detection and photoelectric smoke detection.

Ionization smoke alarms are generally more responsive to flaming fires.

How they work: Ionization-type smoke alarms have a small amount of radioactive material between two electrically charged plates, which ionizes the air and causes current to flow between the plates. When smoke enters the chamber, it disrupts the flow of ions, thus reducing the flow of current and activating the alarm. 

Photoelectric smoke alarms are generally more responsive to fires that begin with a long period of smoldering (called “smoldering fires”).

How they work: Photoelectric-type alarms aim a light source into a sensing chamber at an angle away from the sensor. Smoke enters the chamber, reflecting light onto the light sensor; triggering the alarm.

For best protection, it is recommended both (ionization and photoelectric) technologies be used in homes. In addition to individual ionization and photoelectric alarms, combination alarms that include both technologies in a single device are available.