Science & Technology GK Questions with Answers – Page 19

The energy gap between the valence band and the conduction band decides whether a solid conducts: in silicon the gap is roughly 1.1 electron volts, small enough for heat or light to lift some electrons across it, which is what makes silicon a semiconductor.

The National Institute of Virology is at Pune in Maharashtra and works under the Indian Council of Medical Research; it began in 1952 as the Virus Research Centre and it isolated the virus strain used in developing the indigenous whole virion inactivated vaccine Covaxin.

A toxoid vaccine uses the toxin of a microbe rather than the microbe itself, treated so that it can no longer harm the body but still provokes antibodies; the tetanus and diphtheria vaccines are the two standard examples, and they work because in those diseases it is the toxin that…

The World Health Organization certified the South East Asia Region, India included, as free of wild poliovirus in March 2014, three years after the last case in the country, because certification requires three consecutive years without a case.

Mission Indradhanush was launched on 25 December 2014 to reach children who had received no vaccine or only some of the prescribed doses, and its name refers to the rainbow of vaccines then in the programme.

The Universal Immunization Programme was launched in 1985 and remains the backbone of child immunisation in India, covering tuberculosis, diphtheria, whooping cough, tetanus, polio, measles, rubella and hepatitis B, with further vaccines in selected states.

BCG stands for Bacillus Calmette Guerin, a live attenuated strain of a bovine tuberculosis bacterium, and it is given at or soon after birth under the Universal Immunization Programme to guard against severe forms of childhood tuberculosis.

In 1796 Jenner used material from cowpox, a mild disease of cattle, to protect a boy against smallpox, and the word vaccine itself comes from vacca, the Latin for cow.

Swine flu is an influenza infection of the type first recognised in pigs, and the name itself records the animal in which the virus circulates before it passes to people; once it is in a human population it spreads from person to person by droplets.

Malaria is caused by the protozoan Plasmodium and carried by the female Anopheles mosquito, and kala azar, also called visceral leishmaniasis, is caused by the protozoan Leishmania donovani and carried by the sandfly.

Typhoid is caused by the bacterium Salmonella Typhi, which spreads through food and water contaminated with human waste, and it is prevented both by sanitation and by the typhoid conjugate vaccine.

LHB stands for Linke Hofmann Busch, the German firm whose design Indian Railways adopted at the end of the 1990s and now builds at Kapurthala and other coach factories.

The Chenab bridge on that link stands about 359 metres above the bed of the river, higher than the Eiffel Tower, and is built as a steel arch to span the deep gorge in an earthquake prone and wind swept setting.

The correct answer is A, Gatimaan Express, which began running in 2016 between Delhi and Agra and became India's first semi-high-speed train at 160 kilometres an hour, a speed the Agra route could take because of its straight alignment and fenced sections.

The correct answer is B, the National High Speed Rail Corporation Limited, a company set up specifically to build and later operate high-speed rail in India, with the Union Government and the Governments of Gujarat and Maharashtra as shareholders.

The corridor uses the Shinkansen system, the high-speed technology Japan has run since 1964, and the project is financed largely by a soft loan from Japan carrying a long repayment period and a low rate of interest.

A Vande Bharat rake is a self-propelled electric multiple unit: the traction motors and control equipment are slung under the coaches themselves, so power is spread along the length of the train instead of being concentrated in one vehicle.

The first Vande Bharat Express was flagged off on 15 February 2019, after the train set had been built at the Integral Coach Factory under the name Train 18 and tested on Indian track.

The correct answer is B, the Integral Coach Factory at Chennai, which designed the train set under the project name Train 18 and rolled out the first rake.

Kavach works on the movement of trains: it reads the position and speed of a locomotive from trackside tags, compares that with the signal and the permitted speed, and brakes the train when the driver does not.