The width of the diffraction band varies
inversely as the wavelength
directly as the width of the slit
directly as the distance between the slit and the screen
inversely as the size of the source from which the slit is illuminated
An unpolarised beam of intensity I0 is incident on a pair of nicols making an angle of 60° with each other. The intensity of light emerging from the pair is
I0
I0/2
I0/4
I0/8
A beam of light of wavelength 600 nm from a distant source falls on a single slit 1 mm wide and the resulting diffraction pattern is observed on a screen 2 m away. The distance between the first dark fringes on either side of the central bright fringe is
1.2 cm
1.2 mm
2.4 cm
2.4 mm
When light of wavelength 300 nm falls on a photoelectric emitter, photoelectrons are liberated. For another emitter, light of wavelength 600 nm is suffcient for liberating photoelectrons. The ratio of the work function of the two emitters is
1 : 2
2 : 1
4 : 1
1 : 4
White light is passed through a dilute solution of potassium permanganate. The specturm produced by the emergent light is
band emission spectrum
line emission spectrum
band absorption spectrum
line absorption spectrum
C.
band absorption spectrum
White light is passed through a dilute solution of potassium permanganate. The specturm produced by the emergent light is band absorption spectrum.
If λ1 and λ2 are the wavelengths of the first members of the Lyman and Paschen series respectively, then λ1 : λ2 , is
1 : 3
1 : 30
7 : 50
7 : 108
Activity of a radioactive sample decreases to (1/3)rd of its original value in 3 days. Then,in 9 days its activity will become
(1/27) of the original value
(1/9) of the original value
(1/18) of the original value
(1/3) of the original value
The working of which of the following is similar to that of a slide projector ?
Electron microscope
Scanning electron microsope
Transmission electron microscope
Atomic force microscope
In a transistor the collector current is always less than the emitter current because
collector side is reverse biased and the emitter side is forward biased
a few electrons are lost in the base and only remaining ones reach the collector
collector being reverse biased, attracts less electrons
collector side is forward biased and emitter side is reverse biased