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Railways PYQCBT 1 2016

RRB NTPC · Question 13

An assertion (A) and a reason (R) are given below. Assertion (A): Tungsten filament is used for making light bulbs. Reason (R): Tungsten has a high melting point. Choose the correct option. A. Both A and R are true and R is the correct explanation of A B. Both A and R are true, but R is not the correct explanation of A. C. A is true, but R is false D. A is false, but R is true

  1. C

  2. A

  3. B

  4. D

Show answer & explanation

Answer: (B) A

Explanation

Bulb filaments are made of tungsten, and it is chosen because of its very high melting point (about 3,422 °C), which lets it glow white-hot without melting. So R correctly explains A.