181 On the basis of band theory of solids the semiconductors have _____________________? Physics Medium Full question → A A party filled valence band and totally empty conduction band B A completely filled valence band a totally empty conduction band and a very wide forbidden band C A completely filled valence band a partially filled conduction band and a narrow forbidden band D A partly filled valence band a totally empty conduction band and a wide forbidden band
182 With increase in temperature the electrical conductivity of intrinsic semi conductor___________________? Physics Medium Full question → A Decreases B Increases C Remains same D First increases then decreases
183 Which one has the greatest energy gap ? Physics Medium Full question → A Semi conductor B Conductor C Metals D Non metals
184 A completely filled band is called__________________? Physics Medium Full question → A Conduction band B Valence band C Forbidden band D Core band
185 The band theory of solids explains satisfactorily the nature of_________________? Physics Medium Full question → A Electrical insulators alone B Electrical conductors alone C Electrical semi conductors alone D All of the above
186 If the density of atoms remain same along any direction in a crystal is called__________________? Physics Medium Full question → A Symmetry B Homogeneity C Isotropy D Cleavage
187 The angular position of cells remains the same for a sample of a crystal. This property is called___________________? Physics Medium Full question → A Isotropy B Cleavage C Homogeneity D The external symmetry of form
188 Materials in which valence electrons are tightly bound to their atoms at low temperature are called___________________? Physics Medium Full question → A Semi conductor B Super conductors C Insulators D Conductor
189 A ferromagnet will become fully magnetized at_________________? Physics Medium Full question → A High voltage A.C B Low voltage A.C C Alternating current at its peak value D D.C current at peak value
190 The energy band occupied by the valence electrons is called___________________? Physics Medium Full question → A Energy state B Valence band C ve energy state D conduction band
191 Formation of large molecule by joining small molecules is_________________? Physics Medium Full question → A Fusion B Polymerization C Crystallization D Subtraction
192 A wire is stretched by a force F which causes an extension 1. The energy stored in the wire is____________________? Physics Medium Full question → 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
193 The ration stress to strain in youngs modulus of the material then tension is__________________? Physics Medium Full question → A Directly proportional to extension B Directly proportional to strain C Directly proportional to square of amplitude D Inversely proportional to extension
194 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_________________? Physics Medium Full question → A Stress/strain B (stress/strain) C Stress x strain D (Stress / strain)
195 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 ? Physics Medium Full question → A 0.01J B 0.02J C 0.04J D 1.0J
196 When a force is applied at one end of an elastic wire it produces at strain ∝ in the wire. If y is the youngs modulus of the material of the wire the amount of energy stored per unit volume of the wire is given by_________________? Physics Medium Full question → A Y∝ B 2Y∝ C Y∝/2 D Y∝2
197 A wire of length L is stretched by a length E when a force F is applied at one end. If the elastic limit is not exceeded the amount of energy stored in the wire is_________________? Physics Medium Full question → A FE B (FE) C FE2/L D FE2
198 Which one of the following physical quantities does not have the dimensions of force per unit area ? Physics Medium Full question → A Stress B Strain C Youngs modulus D Pressure
199 What are the dimensions of stress ? Physics Medium Full question → A MLT-2 B ML-2T-1 C ML-1T-2 D ML-T-1
200 Which of the following substances posses the highest elasticity ? Physics Medium Full question → A Rubber B Steel C Glass D Copper