It is a blood group. People whose blood contains this group are referred to as being Rhesus positive. Those who lack it are called Rhesus negative.

Raman Scattering or Raman Effect is the inelastic scattering of a photon. This was first reported by CV Raman for which he was awarded the Nobel prize in 1930. When light is scattered from an atom or a molecule, most photons scatter elastically. However, a small fraction (1 in a million) is scattered inelastically. The frequency of these photons changes, …

लंदन की रीजेंट स्ट्रीट पर स्थित हैमलेज दुनिया की अपने तरह की सबसे बड़ी और सबसे पुरानी खिलौनों की दुकान है। यहाँ अरब देशों के रईस शेख अपने बच्चों के लिए सबसे लेटेस्ट खिलौने खरीदने आतें हैं तो रूसी कुलीन वर्ग के लोग भी अपने बच्चों के लिए ट्रक भर कर यहीं से खिलौने ले जाते हैं। असल में यह …

Radar, or radio location, as it was called in the early days, is the use of radio waves to find the whereabouts of aircraft or ships. Electromagnetic waves, which include radio and light waves, all travel at the same speed. When small bursts of radio waves, fired into space from a transmitter, strike an object such as an aircraft some …

A ‘quasi-resonant’ DC to DC converter with zero-current and zero-voltage switching includes a transformer with primary and secondary windings, and periodic switching means connected in series with the primary winding. The topology of the converter is determined by selecting an input capacitor with a capacitance much lower than the output capacitor.

द्वितीय विश्व युद्ध में अंग्रेजों एवं मित्र देशों की सामरिक शक्ति अधिक होने पर भी आजाद हिन्द फौज के सेनानी उन्हें कड़ी टक्कर दे रहे थे. लेफ्टिनेंट ज्ञानसिंह बिष्ट भी ऐसे ही एक सेनानायक थे, जिन्होंने अपने से छह गुना बड़ी अंग्रेज टुकड़ी को भागने पर मजबूर कर दिया. 16 मार्च, 1945 को ‘सादे पहाड़ी के युद्ध’ में भारतीय सेना …

Push to Talk (PTT), also known as press to transmit, is a method by which we can communicate on halfduplex communication lines, including two-way radio, using a momentary button to switch from voice reception mode to transmit mode. A two-way radio can both transmit and receive (a transceiver), unlike a broadcast receiver which only receives content. Two mobile phones having …

All matter consists of atoms and all atoms have protons along with other subatomic particles. When an accelerated beam of proton is incident on the target tissue like a tumour, due to their relatively enormous size, protons scatter less easily in the tissue and there is very little lateral dispersion. Therefore, the beam stays focused on the tumour shape without …

An eye that suffers from myopia as well as from hypermetropia is said to suffer from presbyopia. A person with this defect cannot see objects distinctly placed at any distance from him. To correct this defect, a person is prescribed bifocal lens that has both types of lenses — convex and concave.

This is the process of using an instrument called polygraph, which is also popularly known as a lie detector.