The angle of incidence for a ray of light at a refracting surface of a prism is 45⁰. The angle of prism is 60⁰. If the ray suffers minimum deviation through the prism, then the […]
A astronomical telescope has objective and eye-piece of focal lengths 40 cm, 4 cm, respectively. To view an object 200 cm away from the objective, the lenses must be seperated by a distance
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In a diffraction pattern due to a singleslit of width a, the first minimum is observed at an angle 30⁰ when light of wavelength 5000Å is incident on the slit. The first secondary maximum is […]
The intensity at the maximum in a Young’s double slit experiment is I₀. Distance between two slits is d=5λ, where λ is the wavelength of light used in the experiment. What will be the intensity […]
An electric dipole is placed at an angle 30°with an electric field intensity 2×10⁵N/C. It experiences a torque equal to 4N-m. The charge on the dipole, if the dipole length is 2cm is,
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When a metallic surface is illuminated with radiation of wavelength λ, the stopping potential is V. If the same surface is illuminating with radiation of wavelength 2λ, the stopping potential is V/4. The threshold wavelength […]
The charge flowing through a resistance R varies with time t as Q=at-bt², where a and b are positive constants. The total heat produced in R is
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(a) a³R/3b (b) a³R/2b (c) […]
A potentiometer wire is 100cm long and a constant potential difference is maintained across it. Two cells are connected in series first to support one another and then in opposite direction. The balance points are […]
If an electron in a hydrogen atom jumps from the 3rd orbit to the 2nd orbit, it emits a photon of wavelength λ. When it jumps from the 4th orbit to the 3rd orbit, the […]
Electrons of mass m with de-Broglie wavelength λ fall on the target in an X-ray tube. The cut-off wavelength (λ₀) of the emitted X-ray is
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(a) λ₀= 2mcλ²/h (b) λ₀= 2h/mc (c) λ₀= […]
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