**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. W**

**hy 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)**