QUES: In a conventional lamp, the evaporated tungsten eventually condenses on the inner surface of the glass envelope, darkening it. For bulbs that contain a vacuum, the darkening is uniform across the entire surface of the envelope. When a filling of inert gas is used, the evaporated tungsten is carried in the thermal convection currents of the gas, depositing preferentially on the uppermost part of the envelope and blackening just that portion of the envelope. An incandescent lamp that gives 93% or less of its initial light output at 75% of its rated life is regarded as unsatisfactory, when tested according to IEC Publication 60064. Light loss is due to filament evaporation and bulb blackening. Study of the problem of bulb blackening led to the discovery of the Edison effect, thermionic emission and invention of the vacuum tube.
What is the IEC guidelines for acceptable level of light loss?

ANS: unanswerable

QUES: In 1976 John Goldsmith introduced autosegmental phonology. Phonological phenomena are no longer seen as operating on one linear sequence of segments, called phonemes or feature combinations, but rather as involving some parallel sequences of features which reside on multiple tiers. Autosegmental phonology later evolved into feature geometry, which became the standard theory of representation for theories of the organization of phonology as different as lexical phonology and optimality theory.
What are no longer seen as operating on lexical phonology?

ANS: unanswerable

QUES: It is estimated that there are around 100 elephants left in Eritrea, the most northerly of East Africa's elephants. The endangered African wild dog (Lycaon pictus) was previously found in Eritrea, but is now deemed extirpated from the entire country. In Gash Barka, deadly snakes like saw-scaled viper are common. Puff adder and red spitting cobra are widespread and can be found even in the highlands.In the coastal areas marine species that are common include dolphin, dugong, whale shark, turtles, marlin/swordfish, and manta ray.
What nonpoisonous snake can be found in Eritrea?

ANS: unanswerable

QUES: Shias believe that Imamah is of the Principles of Faith (Usul al-Din).As the verse 4:165 of quran expresses the necessity to the appointment of the prophets; so after the demise of the prophet who will play the role of the prophet; till the people have not any plea against Allah.So the same logic that necessitated the assignment of prophets also is applied for Imamah.That is Allah Must assign someone similar to prophet in his attributes and Ismah as his successor to guide the people without any deviation in religion. They refer to the verse (...This day I have perfected for you your religion and completed My favor upon you and have approved for you Islam as religion...) 5:3 of Quran which was revealed to the prophet when he appointed Ali as his successor at the day of Ghadir Khumm.
Who must assign a successor after the demise of a prophet?

ANS:
Allah