371. A three-dimensional image is obtained by________________?
A. Electron microscope
B. Scanning electron microscope
C. Magnetic imaging
D. None of the above

372. The uncertainty in momentum & position is due to its_____________?
A. Property of matter and radiation
B. Two-dimensional motion
C. Emission of the certain wavelength
D. Very high velocity

373. For confinement of electron in a box of radius 10-14m the electron, speed should be_____________?
A. 107m/sec
B. Should be greater than the speed of light.
C. Be zero
D. Not be wave-like

374. The energy radiated is directly proportional to the fourth power of Kelvins temperature is________________?
A. Karl-Weins law
B. Rayleigh-Jeans law
C. Stephens law
D. Plancks

375. Compton effect proves the________________?
A. Photon theory of light
B. Dual nature of light
C. Wave nature of light
D. Uncertain nature of light

376. Electron moves in the orbit as________________
A. Simple vibratory motion
B. Standing wave motion
C. Vibratory motion like up and down
D. S.H.M likes the sound

377. A lens which converges a beam of parallel rays to a point is called______________?
A. diverging (or concave) lens
B. converging (or convex) lens
C. plano concave lens
D. plano convex lens

378. The diameter of a lens is called________________?
A. focal length
B. principal axis
C. aperture
D. radius of curvature

379. Unit of power of a lens is________________?
A. meter
B. watt
C. diopter
D. horsepower

380. The power of a concave lens is_______________?
A. real
B. virtual
C. positive
D. negative