Question
The valence band and conduction band of a solid overlap at low temperature, the solid may be(a) A metal(b) A semiconductor(c) An insulator(d) None of these
       

Answer

(a) A metal

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Assertion  :   The surface charge densities of two spherical conductors of different radii are equal. Then the electric field intensities near their surface are also equal.
Reason    : Surface charge density is equal to charge per unit area. (a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.
 
 
 
 
In good conductors of electricity, the type of bonding that exists is(a) Ionic  (b) Vander Waals(c) Covalent(d) Metallic
       
Choose the incorrect statement from the following: When two identical capacitors are charged individually to different potentials and connected parallel to each other after disconnecting them from the source(a) Net charge equals the sum of initial charges(b) The net energy stored in the two capacitors is less than the sum of the initial individual energies(c) The net potential difference across them is different from the sum of the individual initial potential difference(d) The net potential difference across them equals the sum of the individual initial potential differences
 
 
 
 
Assuming that universe is expanding, if the spectrum of light coming from a star which is going away from earth is tested, then in the wavelength of light(a) There will be no change(b) The spectrum will move to infrared region(c) The spectrum will seems to shift to ultraviolet side(d) None of the above
 
 
 
 
A $3$ volt battery with negligible internal resistance is connected in a circuit as shown in the figure.  The current $I,$ in the circuit will be
In Young’s experiment, monochromatic light is used to illuminate the two slits $A$ and $B.$ Interference fringes are observed on a screen placed in front of the slits. Now if a thin glass plate is placed normally in the path of the beam coming from the slit
The angle of dip at a place is 60°. At this place the total intensity of earth's magnetic field is 0.64 units. The horizontal intensity of earth's magnetic field at this place is(a) 1.28 units(b) 0.64 units(c) 0.16 units(d) 0.32 units
       
In a plane electromagnetic wave the phase difference between electric and magnetic field vectors is :
Two protons exerts a nuclear force on each other, the distance between them is
A point object is placed at the center of a glass sphere of radius 6 cm and refractive index 1.5. The distance of the virtual image from the surface of the sphere is(a) 2 cm(b) 4 cm(c) 6 cm  (d) 12 cm