546: Antigen is a substance which
(a) lowers body temperature
(b) destroys harmful bacteria
(c) triggers the immune system
(d) is used as an antidote to poison
Explanation:
Antigen is a proteinous substance which, when introduced into the tissue stimulates antibody production (immune system). It may be living or non living in nature. For ex. : Bacteria or virus that enters into our body either naturally or artificially acts as antigen and stimulates antibody production.
547: Micro-elements needed to increase soil fertility are:
(a) Nitrogen, hydrogen and calcium
(b) Nitrogen, phosphorus and potassium
(c) Iron, calcium and potassium
(d) Manganese, copper and zinc
548: In a dry cell (battery), which of the following are used as electrolytes?
(a) Ammonium chloride and Zinc chloride
(b) Sodium chloride and Calcium chloride
(c) Magnesium chloride and Zinc chloride
(d) Ammonium chloride and Calcium chloride
Explanation:
2. Zinc-carbon dry cell or battery is packaged in a zinc can that serves as both a container and anode. It was developed from the wet Leclanche cell. The cathode is a mixture of manganese dioxide and carbon powder. The electrolyte is a past of zinc chloride and ammonium chloride dissolved in water. Zinc chloride cells are an improved version from the original ammonium chloride variety. Zinc-carbon batteries are the least expensive primary batteries and thus a popular choice by manufacturers when devices are sold with batteries included. They can be used in remote controls, flashlights, toys, or transistor radios, where the power drain is not too heavy.
549: What is the purpose of evolved Laser Interferometer Space Antenna (eLISA) project?
(a) To detect neutrinos
(b) To detect gravitational waves
(c) To detect the effectiveness of missile defence system
(d) To study the effect of solar flares on our communication systems
550: With reference to communication technologies, what is/are the difference/differences between LTE (Long-Term Evolution) and VoLTE (Voice over Long-Term Evolution)?
1. LTE is commonly marketed as 3G and VoLTE is commonly marketed as advanced 3G.
2. LTE is data-only technology and VoLTE is voice-only technology.
Select the correct answer using the code given below.
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Explanation:
LTE improved on the radio technology of 3Gs WCDMA and introduced OFDM or Orthogonal Frequency-Division Multiplexing. ITU (The International Telecommunication Union) recognises the lack of clarity in the term 4G and has determined LTE-Advanced and WirelessMAN-Advanced or WiMax 2 as "True" 4G.
VoLTE is a technology update to the LTE protocol used by mobile phone networks. Under LTE, the infrastructure of telecom players only allows transmission of data while voice calls are routed to their older 2G or 3G networks.
Basically VoLTE systems covert voice into data stream, which is then transmitted using the data connection.
Source: https://www.thehindubusinessline.com/opinion/columns/slate/all-you-wanted-to-know-about-volte/article9864031.ece
http://tec.gov.in/pdf/Studypaper/Study%20Paper%20on%20VoLTE%20-%20Final%20(1).pdf