Long before experiments could detect gamma-rays emitted by cosmic sources, scientists had known that the Universe should be producing such high energy photons. Hard work by several brilliant scientists had shown us that a number of different processes which were occurring in the violent Universe would result in gamma-ray emission. These processes included cosmic ray interactions with interstellar gas, supernova explosions, and interactions of energetic electrons with magnetic fields. In the 1960s, we finally developed the ability to actually detect these emissions and we have been looking at them ever since.
Gamma-rays coming from space are mostly absorbed by the Earth's atmosphere. So gamma-ray astronomy could not develop until it was possible to get our detectors above all, or most, of the atmosphere, using balloons or spacecraft. The first gamma-ray telescope carried into orbit, on the Explorer XI satellite in 1961, picked up fewer than 100 cosmic gamma-ray photons. These appeared to come from all directions in the Universe, implying some sort of uniform "gamma-ray background". Such a background would be expected from the interaction of cosmic rays (very energetic charged particles in space) with gas found between the stars.
Additional gamma-ray experiments flew on the OGO, OSO, Vela, and Russian Cosmos series of satellites. However, the first satellite designed as a "dedicated" gamma-ray mission was the second Small Astronomy Satellite (SAS-2) in 1972. It lasted only seven months due to an electrical problem, but provided an exciting view into the high-energy Universe (sometimes called the 'violent' Universe, because the kinds of events in space that produce gamma-rays tend to be explosions, high-speed collisions, and such!). In 1975, the European Space Agency launched a similar satellite, COS-B, which operated until 1982. These two satellites, SAS-2 and COS-B, confirmed the earlier findings of the gamma-ray background, and also detected a number of point sources. However, the poor resolution of the instruments made it impossible to identify most of these point sources with individual stars or stellar systems.
Why is the high energy Universe called the 'violent' Universe?
There are high speed collisions and explosions.
Dust particles and thunder strike the Universe.
A lot of chaos happens in the Universe.
The Universe is always termed as violent.
Answer: Option A.
Refer to “ Sometimes called the 'violent' Universe, because the kinds of events in space that produce gamma-rays tend to be explosions, high-speed collisions, and such”.
Gamma-rays could not be detected before 1961 because
satellites were unable to detect them.
gamma-rays are absorbed by the Earth's atmosphere and detected by telescopes placed in space only.
the source of gamma-rays was not known.
telescopes were not capable to detect gamma-rays.
Answer: Option B.
Refer to “Gamma-rays coming from space are mostly absorbed by the Earth's atmosphere. So gamma-ray … into orbit, on the Explorer XI satellite in 1961”
According to scientists, what led to the emission of gamma-rays?
A high energy Universe forces gamma-rays emission.
The different processes occurring in the Universe.
The collisions in the Universe.
Scientists don't have an answer to this.
Answer: Option B.
Refer to “Hard work by several brilliant scientists …………..result in gamma-ray emission. These processes included cosmic ray interactions ….. with magnetic fields”.
What was the drawback in the two satellites SAS-2 and COS-B?
These two satellites met with a crash.
They were short lived.
They failed during the launch.
They carried instruments with low resolution.
Answer: Option D.
Refer to “These two satellites, SAS-2 and COS-B…. the poor resolution of the instruments made it impossible to identify most of these point sources with individual stars or stellar systems”.
DIRECTIONS for questions 5 to 8 : Each question has a group of sentences marked A, B, C, D and E. Arrange these to form a logical sequence.
A. The upsurge of public activism against the setting up of Special Economic Zones, which eventually forced the State government to announce the scrapping of all 15 such projects, is an impressive case in point.
B. Early last year, a similar agitation coerced the government into calling for a revision of the Goa Regional Plan 2Q11, a controversial document that opened up large swathes of land, including green belts and coastal stretches, for construction.
C. The broad-based agitation against SEZs has demonstrated the power of popular protest in the State.
D. Those opposed to the projects had questioned the propriety of the government acquiring large tracts of land and then selling them to promoters at low prices.
E. A coastal State with an area of 3,700 square kilometers and a population of about 1.4 million, Goa has always been extremely sensitive to the impact of unrestrained economic development.
BCDEA
CDEAB
EABCD
DABCE
Answer: Option C.
Sentence E introduces ‘Goa that has been extremely sensitive to the impact of unrestrained economic development’.
A exemplifies on ‘the upsurge.
B carries the idea forward with ‘a similar agitation’
A. The post-election crisis in Kenya remains unresolved.
B. The damage being done to the country's economy is severe: tourism, horticulture, and other industries that depend on trade beyond the Kenyan border are reeling.
C. Many countries responded, providing essential humanitarian assistance and logistical support. For this, I and many other Kenyans are very grateful.
D. Thousands of livelihoods, along with investments throughout the region, are threatened and collapsing.
E. As the situation in Kenya escalated with murders, rapes, burning of property, looting, and the displacement of thousands of people throughout the country - the international community was urged to help.
AEDBC
ABCED
ACDEB
ABDEC
Answer: Option D.
The passage is about crisis in Kenya which is introduced in A. B takes it further by explaining the damage to the economy. D follows by further explaining the damage that they are threatened and collapsing. E mentions the international community was ready to help.
C follows elaborating on the help.
The EC link is only present in the D option The EC link is only present in the D option
A. The US market will continue to be the dominant one in the foreseeable future. The rupee could become even stronger.
B. A greater recourse to hedging as well as striving for multi-currency revenue streams automatically suggests itself.
C. Already one company, Dell, by resorting to these methods extensively has turned in an above - average performance during the first quarter.
D. Most IT companies have been grappling with more mundane problems such as a high level of attrition amidst rising wage costs and inability to secure the right type and number of American visas.
E. The BPO industry and many medium-sized software exporters are reportedly operating on thin margins.
BCADE
ABCDE
DCBAE
EDABC
Answer: Option D.
BC will form a pair.
The problems are listed in E, D and A.
B which gives a course of action should follow them.
A. Last March, I was invited to present a paper on the topic of whether the mistakes of the 20th century would be repeated in the 21st century as well.
B. The economic crisis hadn't become grave then.
C. But today the world is in the midst of the biggest economic crisis since 1929.
D. The key difference between then and now is that the old power structures have finally disappeared.
E. Now even the US is pleading for financial help from China
BCADE
ABCDE
CDEAB
DEABC
Answer: Option B
BC shows a contrast and forms a pair, CD forms a pair, A is the opening sentence.
DIRECTIONS for questions 9 to 10: Choose the option which gives the best way of writing the sentence ensuring that the message is correctly conveyed.
1. There were great stable, where a dozen grooms and boys held forth, rows of vine-clad servant cottages, an endless and orderly array of outhouses, long grape arbors, green pastures, orchards, and berry patches.
2. There were great stables, where a dozen grooms and boys held forth, rows of vine-clad servants' cottages, an endless and orderly array of outhouses, long grape arbors, green pastures, orchards, and berry patches.
3. There are great stables, where a dozen grooms and boys held forth, rows of vine-clad servants' cottages, an endless and order array of outhouses, long grape arbors, green pastures, orchards, and berry patches.
4. There were great stables, where a dozen grooms and boys held forth, rows of vine-clad servant's cottages, an endless and orderly array of outhouse, long grape arbor, green pasture, orchard, and berry patch.
1
2
3
4
Answer: Option B.
In the 1st sentence- ‘stable’ does not agree with ‘were’, so a subject verb agreement error.
2nd sentence-correct.
3rd sentence- there ‘are’, the rest of the sentence is in past tense, so there is a tense mismatch.
4th sentence- servant’s, should be servants’.
1. Then there is the pumping plant for the artesian well, and the big cement tank where Judge Miller's boys took their morning plunge and kept cool in the hot afternoon.
2. Then there was the pumping plant for the artesian well, and the big cement tank where Judge Miller's boys took their morning plunge and kept cool in the hot afternoon.
3. Then there was the pumping plant for the artesian well, and the big cement tank were Judge Miller's boys took their morning plunge and keep cool in the hot afternoon.
4. Then there was the pumping plant though the artesian well, and the big cement tank where Judge Miller's boys took their morning plunge and kept cool in the hot afternoon.
1
2
3
4
Answer: Option B.
1st sentence- there is a tense mismatch..
2nd sentence- correct.
3rd sentence- ‘keep’ cool should be kept.
4th sentence – ‘through’ the artesian well is incorrect.
