Related InterviewSolutions

• if e/m of electron is `1.76xx10^(11)C(kg)^(-1)` andn stopping potential is 0.71 V, then the maximum velocity of the photoelectron isA. `150kms^(-1)`B. `200kms^(-1)`C. `500kms^(-1)`D. `250kms^(-1)`
• The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately:A. 540 nmB. 400 nmC. 310 nmD. 220 nm
• A beam of cathode rays is subjected to crossed electric (E ) and magnetic fields (B). The fields are adjusted such that the beam is not deflected. The specific charge of the cathode rays is given byA. `(B^(2))/(2VE^(2))`B. `(2VB^(2))/(E^(2))`C. `(2VE^(2))/(B^(2))`D. `(E^(2))/(2VB^(2))`
• If 5% of the energy supplied to a bulb is irradiated as visible light, how many quanta are emitted per second by a 100 W lamp? (Assume, wavelength of visible light as `5.6xx10^(-5)cm`)A. `1.4xx10^(19)`B. `3xx10^(3)`C. `1.4xx10^(-19)`D. `3xx10^(4)`
• Which of the following figure represents the variation of particle momentum and the associated de - Broglie wavelength ?A. B. C. D.
• In a cathode ray oscillograph, the focusing of beam on the screen is achieved byA. convex lensesB. magnetic fieldC. electric potentialD. all of these
• When a cathode ray tube is operated at 2912 V, the velocity of electrons is `3.2xx10^(7)ms^(-1)`. Find the velocity of cathode ray if the tube is operated at 5824V.A. `2.4xx10^(7)ms^(-1)`B. `5.2xx10^(7)ms^(-1)`C. `4.525xx10^(7)ms^(-1)`D. `2.4xx10^(6)ms^(-1)`
• A particle of mass `1 mg` has the same wavelength as an electron moving with a velocity of `3 xx 10^(6) ms^(-1)`. The velocity of the particle isA. `3xx10^(-31)ms^(-1)`B. `2.7xx10^(-21)ms^(-1)`C. `2.7xx10^(-18)ms^(-1)`D. `9xx10^(-2)ms^(-1)`
• Monochromatic light of frequency `6.0 xx 10^(14) Hz` is produced by a laser. The power emitted is `2 xx 10^(-3)` w. The number of photons emitted, on the average, by the sources per second isA. `5xx10^(16)`B. `5xx10^(16)`C. `5xx10^(17)`D. `5xx10^(14)`
• The work function for aluminium is 4.125 eV. The cut-off wavelength for photoelectric effect for aluminium will beA. 420 nmB. 350 nmC. 300 nmD. 200 nm