761. A wire suspended vertically from one end is stretched by attaching a weight of 20N to the lower end. The weight stretches the wire by 1mm. How much energy is gained by the wire ?
A. 0.01J
B. 0.02J
C. 0.04J
D. 1.0J

762. A certain stress applied to an elastic material produces a certain strain in it. If the elastic limit is not exceeded the energy gained per unit volume of the material is given by_________________?
A. Stress/strain
B. (stress/strain)
C. Stress x strain
D. (Stress / strain)

763. The ration stress to strain in youngs modulus of the material then tension is__________________?
A. Directly proportional to extension
B. Directly proportional to strain
C. Directly proportional to square of amplitude
D. Inversely proportional to extension

764. A wire is stretched by a force F which causes an extension 1. The energy stored in the wire is____________________?
A. The extension of the wire is proportional to the force applied
B. The weight of the wire is negligible
C. The wire is not stretched beyond its elastic limit
D. The cross sectional area of the wire remains constant

765. Formation of large molecule by joining small molecules is_________________?
A. Fusion
B. Polymerization
C. Crystallization
D. Subtraction

766. The energy band occupied by the valence electrons is called___________________?
A. Energy state
B. Valence band
C. ve energy state
D. conduction band

767. A ferromagnet will become fully magnetized at_________________?
A. High voltage A.C
B. Low voltage A.C
C. Alternating current at its peak value
D. D.C current at peak value

768. Materials in which valence electrons are tightly bound to their atoms at low temperature are called___________________?
A. Semi conductor
B. Super conductors
C. Insulators
D. Conductor

769. The angular position of cells remains the same for a sample of a crystal. This property is called___________________?
A. Isotropy
B. Cleavage
C. Homogeneity
D. The external symmetry of form

770. If the density of atoms remain same along any direction in a crystal is called__________________?
A. Symmetry
B. Homogeneity
C. Isotropy
D. Cleavage