00353nam a2200145 a 450000500170000002000150001708200130003210000170004524500360006225000110009826000430010930000210015270000170017370000170019020251203110635.0  a8170145104  a530bSEH  aSehgal, N.K.  aPractical PhysicsbFor Class XI  a3rd ed  aNew DelhibSultan Chand & Sons.,c1998  a352p.c24 cm. PB  aChopra, K.L.  aSehgal, D.L.