Daily Quiz: UPSC Prelims Marathon – March 29, 2018

Statement 1 is correct.  Aqua regia, mixture of concentrated nitric and hydrochloric acids. The traditional solution is comprised of a 3:1 mixture of hydrochloric acid and nitric acid, respectively.

Statement 2 is incorrect.

It is commonly used to remove noble metals such as gold, platinum and palladium from substrates, particularly in microfabrications and microelectronics labs.  Glassware may also be washed with aqua regia to remove organic compounds only in trace amounts. Aqua regia solutions are extremely corrosive and may result in explosion or skin burns if not handled with extreme caution.

All of the above diseases can be transmitted from one person to another through tattooing.

Syphilis: Syphilis is a sexually transmitted infection (STI) caused by the bacteria Treponema pallidium.

Hepatitis B: Hepatitis B (HBV, Hep B), a virus spread through infected blood or body secretions (blood, semen, vaginal discharge, breast milk, and saliva).

Both the statements are correct.

A rainbow is a natural spectrum appearing in the sky after a rain shower. It is caused by dispersion of sunlight by tiny water droplets, present in the atmosphere. A rainbow is always formed in a direction opposite to that of the Sun.

The water droplets act like small prisms. They refract and disperse the incident sunlight, then reflect it internally, and finally refract it again when it comes out of the raindrop. Due to the dispersion of light and internal reflection, different colours reach the observer’s eye.

Statement 1 and 2 are correct. Thorium is a naturally-occurring, slightly radioactive metal discovered in 1828 by the Swedish chemist Jons Jakob Berzelius, who named it after Thor, the Norse god of thunder. It is found in small amounts in most rocks and soils, where it is about three times more abundant than uranium

The most common source of thorium is the rare earth phosphate mineral, monazite, which contains up to about 12% thorium phosphate, but 6-7% on average. Monazite is found in igneous and other rocks but the richest concentrations are in placer deposits, concentrated by wave and current action with other heavy minerals.

Statement 3 is incorrect. Thorium (Th-232) is not itself fissile and so is not directly usable in a thermal neutron reactor. However, it is ‘fertile’ and upon absorbing a neutron will transmute to uranium-233 (U-233), which is an excellent fissile fuel materialb. Thus, Thorium fuels need a fissile material as a ‘driver’ so that a chain reaction (and thus supply of surplus neutrons) can be maintained. The only fissile driver options are U-233, U-235 or Pu-239.

The list of fuels that can be derived from algae includes:

Biodiesel

Butanol

Gasoline

Methane

Ethanol

Vegetable Oil

Jet Fuel

The term third generation biofuel has only recently enter the mainstream it refers to biofuel derived from algae.

Both the statements are correct.  Laser light is different from normal.  Laser light contains only one wavelength (one specific color). The particular wavelength of light is determined by the amount of energy released when the excited electron drops to a lower orbit.

Laser light is directional. Whereas a laser generates a very tight beam, a flashlight produces light that is diffuse. Because laser light is coherent, it stays focused for vast distances, even to the moon and back.

Both the statements are correct. Hot air balloons fly when the air inside the hot air balloon is less dense than the air surrounding it. Hot air is less dense than cool air; the heated air causes the balloon to rise simply because it is lighter than an equal volume of cold air. Buoyancy is an upward force that the air exerts, and it helps hot-air balloons and blimps stay in the air. There will not be any control over the horizontal flight path.