Directions: In the following questions, a statement of assertion (A) ...
Tungsten is selected for making filaments of incandescent lamp bulbs because tungsten can sustain high temperature and it has a high melting point, with high resistivity.
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Directions: In the following questions, a statement of assertion (A) ...
Assertion: Tungsten metal is used for making filaments of incandescent lamps.
Reason: The melting point of tungsten is very low.
The correct answer is option 'C': Assertion (A) is true but reason (R) is false.
Explanation:
To understand why option 'C' is the correct answer, let's analyze the assertion and reason given in the question.
Assertion (A): Tungsten metal is used for making filaments of incandescent lamps.
This assertion is true. Tungsten metal is indeed used for making filaments of incandescent lamps. This is because of its unique properties that make it suitable for this purpose. Tungsten has a very high melting point, it has good electrical conductivity, and it can withstand high temperatures without melting or deforming easily. These properties make tungsten an ideal material for the filaments of incandescent lamps.
Reason (R): The melting point of tungsten is very low.
This reason is false. In fact, tungsten has one of the highest melting points of all metals. It has a melting point of around 3,410 degrees Celsius (6,170 degrees Fahrenheit). This high melting point is one of the reasons why tungsten is used in the filaments of incandescent lamps. The filament gets heated up to very high temperatures, and tungsten's high melting point allows it to withstand these temperatures without melting.
Therefore, the reason given in option 'R' is incorrect. The melting point of tungsten is not low; it is actually very high. However, the assertion in option 'A' is true. Tungsten is indeed used for making filaments of incandescent lamps because of its high melting point and other desirable properties.
Hence, the correct answer is option 'C': Assertion (A) is true but reason (R) is false.
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