[PPSC SOs (Ballistics, Documents Photography, AudioVoice) SAs (Ballistics, Photography AudioVoice) 2023]
41. Recently, scientists observed the merger of two ‘black holes’ billions of light years away from the Earth. What is the significance of these observations?
Existence of ‘black holes’ was confirmed
Higgs Bosons particles were detected
'Gravitational Waves’ were detected
Einstein’s Special Theory of Relativity was proved
42. Why do Step index Single mode fibers are used in long distance communication?
Select the correct answer(s). 1. Low signal loss in single mode fiber 2. No modal dispersion in single mode fiber 3. Single mode fiber has high modal dispersion 4. Refractive index of single mode fiber gradually changes, this will help in long distance communication.
1 and 3 only
1 and 2 only
2 and 4 only
3 and 4 only
43. The energy band gap of a semiconductor
Increases with increase in T
Decreases with increase in T
Does not vary with change in T
Changes as a function of T & H
44. Which act led to the Jallianwala Bagh incident?
Defence of India Act
Rowlatt Act
Government of India Act
Official secrets Act
45. Who among the following is the famous architect of pre-independence Punjab who prepared the architectural design of Khalsa College?
John Lockwood Kipling
Bhai Ram Singh
Sir Ganga Ram
Bhai Jodh Singh