To get output for the following circuit, the correct choice for the input is,
A=1, B=0, C = 0
A=1, B=1, C = 0
A=1, B=0, C=1
A=1, B=0, C=1
When a metallic surface is illuminated with radiation of wavelength , the stopping potential is V. If the same surface is illuminated with radiation of wavelength 2 , the stopping potential is V/4. The threshold wavelength for the metallic surface is,
3
3
The intensity at the maximum in a Young's double slit experiment is Io. Distance between two slits is d = , where is the wavelength of light used in the experiment. What will be the intensity infront of one of the slits on the screen placed at a distance D = 10 d?
3
Given the value of rydberg constant is 10 m-1, the wave number of the last line of the Balmer series in hydrogen spectrum will be:
0.5 x 107 m-1
0.25 x 107 m-1
2.5 x107 m-1
2.5 x107 m-1
The ratio of escape velocity at earth (Ve) to the escape velocity at a planet (vp) whose radius and mean density are twice as that of earth is,
1:
1:4
1:
1:
A siren emitting a sound of frequency 800 Hz moves away from an observer towards a cliff at a speed of 15 m/s. Then, the frequency of sound that the observer hears in the echo reflected from the cliff is (Take, velocity of sound in air = 330 m/s)
800 Hz
838 Hz
885 Hz
885 Hz
In a diffraction pattern due to single slit of width a, the first minimum is obsrved at an angle 30o when light of wavelength is incident on the slit. The first secondary maximum is observed at an angle of:
sin-1 (2/3)
sin-1 (1/2)
sin-1 (3/4)
sin-1 (3/4)
A black body is at a temperature of 5760 K. The energy of radiation emitted by the body at wavelength 250 nm is U1, at wavelength 500 nm is U2 and that at 1000 nm is U3. Wien's constant, b = 2.88 x 106 nmK. Which of the following is correct?
U3 = 0
U1 > U2
U2 > U1
U2 > U1
Consider the junction diode as ideal. The value of current flowing through AB is,
10-2 A
10-1 A
10-3 A
10-3 A
An astronomical telescope has objective eyepiece of focal lengths 40 cm and 4 cm respectively. To view an object 200 cm away from the objective lens, the lenses must be separated by a distance,
46.0 cm
50.0 cm
54.0 cm
37.3 cm
C.
54.0 cm
According to a question,
Focal length of the objective lens, Fo = +40 cm
Focal length of eyepiece, Fe = 4 cm
Object distance for objective lens (uo) = -200 cm
Applying lens formula for objective lens,
Image will be formed at the focus of a eyepiece lens.
So, for normal adjustment distance between objectives and eyepiece (length of tube) will be,