1. If we completely remove air from an electric bulb, it will prevent
- bursting of the bulb
- loss of light
- oxidation of tungsten
- electric shock
Answer: (3)
2. Why does the filament of an electric bulb lamp becomes white hot but the lead - in wires holding the filament are slightly heated:
- Because it is made up of black iron
- Because of its low resistance
- Because of its high melting point
- None of the above
Answer: (2)
3. Radioactivity is implemented in the field of
- agriculture
- industry
- all of the above
- none of the above
Answer: (3)
4. Heavy nucleus can be split into roughly two equal fragments with the emission of energy by the process of
- Fission
- Fusion
- Transmutation
- Photoelectric Effect
Answer: (1)
5. Radiocarbon dating technique is used
- to estimate formation of rocks
- to estimate the age of soil
- to estimate the age of fossils
- both (1) & (2)
Answer: (3)
6.When we make a fuse wire, the selected material should have
- low melting point
- high melting point
- high resistivity
- low resistivity
Answer: (1)
7. Soundness of cement is usually the measure of
- its strength
- its durability
- its volume change on setting
- its permeability
Answer: (3)
8. Which one of the following is the velocity ratio of a first system of pulleys with four pulleys
- 20
- 5
- 9
- 16
Answer: (4)
9. What will be the new the eddy current loss, if the old eddy current loss in a transformer is 100W with f=60 Hz and the thickness t of laminations = 0.4 mm with f=50Hz and t=0.2mm
- 20.12W
- 14.2W
- 17.36W
- 18.36W
Answer: (3)
10. Which one is the best example of semiconductor
- copper
- silver
- mica
- germanium
Answer: (4)
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