Which of the following is used in the oven? (1) X-rays (2) UV rays (3) Microwaves (4) Radiowaves Answer: (3) An oven that uses micro radiation waves as a source of heat to cook food as opposed to a fire source. Conceptualized in 1946, Dr Perry Spencer allegedly discovered the healing properties of microwaves while studying … Read more
How much calorie of energy is released by a boiled egg? (1) 40 (2) 50 (3) 60 (4) 77 Answer: (4) 77-78 calories are released in a large size boiled egg. Boiled eggs are eggs (typically chicken eggs) cooked by immersion in boiling water with their shells unbroken.
Who among the following developed the technology of underground nuclear explosion? (1) Dr. Homi J. Bhabha (2) Dr. Vikram Sarabhai (3) Dr. Raja Ramanna (4) Dr. P. K. Iyengar Answer: (1) Homi Jehangir Bhabha was an Indian nuclear physicist, founding director, and professor of physics at the Tata Institute of Fundamental Research. Colloquially known as “father … Read more
“Curie” is a unit of : (1) Radioactivity (2) Temperature (3) Heat (4) Energy Answer: (1) Curie, in physics, a unit of activity of a quantity of a radioactive substance, was named in honour of the French physicist Marie Curie. One curie (1 Ci) is equal to 3.7 × 1010 becquerel (Bq). Radioactivity refers to the … Read more
What is the minimum escape velocity of the rocket to be launched into space? (1) 5 Km/Sec. (2) 6 Km/Sec. (3) 11 Km/Sec. (4) 15 Km/Sec. Answer: (3) On the surface of the Earth, the escape velocity is about 11.2 kilometres per second (~6.96 mi/s), which is approximately 34 times the speed of sound (Mach 34) … Read more
For which Diode is used ? (1) modulation (2) oscillation (3) amplification (4) purification Answer: (4) The most common function of a diode is to allow an electric current to pass in one direction (called the diode’s forward direction), while blocking current in the opposite direction (the reverse direction).This unidirectional behavior is called recti fication or … Read more
Ultraviolet radiations of the Sun do not reach the earth because the earth’s atmosphere is surrounded by (1) Carbon dioxide (2) Ammonia (3) Chlorine (4) Ozone Answer: (4) The ozone layer absorbs 97–99% of the Sun’s medium-frequency ultraviolet light (from about 200 nm to 315 nm wavelength), which potentially damages exposed life forms on Earth. Ozone … Read more
Which of the following statements is true when we see ‘rainbow’? (1) We face sun and raindrops (2) The Sun remains behind us and we face raindrops (3) In light rainfall, we face Sun (4) The sky remains clear and the sun is at a lower position in the sky Answer: (2) We see rainbows because … Read more
The plastic material commonly used for making gear wheels is (1) Polyesters (2) Nylons (3) Bakelit (4) Polystyrene Answer: (2) Popular materials for plastic gears are acetal resins such as DELRIN, Duracon M90; nylon resins such as ZYTEL, NYLATRON, MC901 and acetal copolymers such as CELCON. The physical and mechanical properties of these materials vary with … Read more
One Kilowatt-hour is equal to— (1) 3.6 Mega Joule (2) 3.8 Mega Joule (3) 3.2 Mega Joule (4) 4.0 Mega Joule Answer: (1) The energy 1 kilowatt-hour (kWh) is 3600000 joules or 3.6 megajoules. In physics, energy is an indirectly observed quantity that is often understood as the ability of a physical system to do work … Read more