Two springs of force constant 1000 N/m & 2000 N/m are stretched by same force. The ratio of their respective potential energies is
2:1
1:2
4:1
1:4
potential energy PE = 12KX2 ; K=force constant; x = displacement restoring force =F =-KX ⇒FK=-X ; substitute X value in PE equation, PE =12KF2K2 =12F2K for two springs, PE1 =12F2K1 PE2 =12F2K2 divide the above two equations, one by the other PE1 PE2=K2K1 ; substitute the given vales of K1,K2 PE1 PE2==20001000=21