NextMockપરીક્ષાઓ શોધો, દા.ત. SSC CGL, UPPSC, Lekhpal
State PCS PYQPrelims 2019

UPPCS · પ્રશ્ન 128

Arrange the following substances in chronological order of their first synthesis in the lab: 1. Black gold 2. Fullerene 3. Graphene 4. Kevlar Select the correct answer from the codes given below:

  1. 1, 2, 3, 4
  2. 4, 2, 3, 1
  3. 2, 4, 3, 1
  4. 4, 1, 2, 3
જવાબ બતાવો અને સમજૂતી

જવાબ: (B) 4, 2, 3, 1

સમજૂતી

Kevlar (1965, Stephanie Kwolek) → Fullerene (1985) → Graphene (isolated 2004) → 'Black gold' (nano-gold-based material, TIFR, 2017). So 4, 2, 3, 1.