Physics-
General
Easy

Question

The ionisation potential of H-atom is 13.6 V. When it is excited from ground state by monochromatic radiations of 970.6 Å, the number of emission lines will be (according to Bohr’s theory)

  1. 10    
  2. 8    
  3. 6    
  4. 4    

The correct answer is: 6


    fraction numerator 1 over denominator lambda end fraction equals R open square brackets fraction numerator 1 over denominator n subscript 1 end subscript superscript 2 end superscript end fraction minus fraction numerator 1 over denominator n subscript 2 end subscript superscript 2 end superscript end fraction close square brackets
    rightwards double arrow fraction numerator 1 over denominator 970.6 cross times 1 0 to the power of negative 10 end exponent end fraction equals 1.097 cross times 1 0 to the power of 7 end exponent open square brackets fraction numerator 1 over denominator 1 to the power of 2 end exponent end fraction minus fraction numerator 1 over denominator n subscript 2 end subscript superscript 2 end superscript end fraction close square brackets rightwards double arrow n subscript 2 end subscript equals 4
    thereforeNumber of emission lines N equals fraction numerator n left parenthesis n minus 1 right parenthesis over denominator 2 end fraction equals fraction numerator 4 cross times 3 over denominator 2 end fraction equals 6

    Related Questions to study

    General
    Physics-

    A 7Li target is bombarded with a proton beam current of 10-4A for 1 hour to produce. 7Be of activity 1.8 x 108 disintegrations per second. Assuming that one 7Be radioactive nucleus is produced by bombarding 1000 protons. Half life of 7Be is ………….. (approx.)

    A 7Li target is bombarded with a proton beam current of 10-4A for 1 hour to produce. 7Be of activity 1.8 x 108 disintegrations per second. Assuming that one 7Be radioactive nucleus is produced by bombarding 1000 protons. Half life of 7Be is ………….. (approx.)

    Physics-General
    General
    Physics-

    The mean lives of a radioactive substance are 1620 years and 405 years for alpha -emission and beta -emission respectively. The time during which three fourth of a sample will decay if it is decaying both by alpha -emission and beta -emission simultaneously.

    The mean lives of a radioactive substance are 1620 years and 405 years for alpha -emission and beta -emission respectively. The time during which three fourth of a sample will decay if it is decaying both by alpha -emission and beta -emission simultaneously.

    Physics-General
    General
    Physics-

    A strong magnetic field is applied on a stationary electron, then

    A strong magnetic field is applied on a stationary electron, then

    Physics-General
    parallel
    General
    Physics-

    Three particles having their charges in the ratio of 1 : 3 : 5 produce the same spot on the screen in Thomson’s experiment. Their masses are in the ratio of

    Three particles having their charges in the ratio of 1 : 3 : 5 produce the same spot on the screen in Thomson’s experiment. Their masses are in the ratio of

    Physics-General
    General
    Physics-

    A wire carrying current I and other carrying 2I in the same direction produces a magnetic field B at the mid point. What will be the field when 2I wire is switched off

    A wire carrying current I and other carrying 2I in the same direction produces a magnetic field B at the mid point. What will be the field when 2I wire is switched off

    Physics-General
    General
    Physics-

    A coil having N turns carry a current I as shown in the figure. The magnetic field intensity at point P is

    A coil having N turns carry a current I as shown in the figure. The magnetic field intensity at point P is

    Physics-General
    parallel
    General
    Physics-

    Which of the following gives the value of magnetic field according to, Biot-Savart’s law'.

    Which of the following gives the value of magnetic field according to, Biot-Savart’s law'.

    Physics-General
    General
    Physics-

    Which of the following will have the least value of fraction numerator q over denominator m end fraction

    Which of the following will have the least value of fraction numerator q over denominator m end fraction

    Physics-General
    General
    Physics-

    One Tesla is equal to

    One Tesla is equal to

    Physics-General
    parallel
    General
    Physics-

    The correct graph between the maximum energy of a photoelectron and the inverse of wavelength of the incident radiation is given by the curve

    The correct graph between the maximum energy of a photoelectron and the inverse of wavelength of the incident radiation is given by the curve

    Physics-General
    General
    Physics-

    The value of stopping potential in the following diagram

    The value of stopping potential in the following diagram

    Physics-General
    General
    Physics-

    The intensity of X-rays from a Coolidge tube is plotted against wavelength as shown in the figure. The minimum wavelength found is lambda subscript c end subscript and the wavelength of the K subscript alpha end subscriptline is lambda subscript k end subscript. As the accelerating voltage is increased

    The intensity of X-rays from a Coolidge tube is plotted against wavelength as shown in the figure. The minimum wavelength found is lambda subscript c end subscript and the wavelength of the K subscript alpha end subscriptline is lambda subscript k end subscript. As the accelerating voltage is increased

    Physics-General
    parallel
    General
    Physics-

    In an experiment on photoelectric effect the frequency f of the incident light is plotted against the stopping potential V subscript 0 end subscript. The work function of the photoelectric surface is given by (e is electronic charge)

    In an experiment on photoelectric effect the frequency f of the incident light is plotted against the stopping potential V subscript 0 end subscript. The work function of the photoelectric surface is given by (e is electronic charge)

    Physics-General
    General
    Physics-

    The stopping potential V for photoelectric emission from a metal surface is plotted along Y-axis and frequency n of incident light along X-axis. A straight line is obtained as shown. Planck's constant is given by

    The stopping potential V for photoelectric emission from a metal surface is plotted along Y-axis and frequency n of incident light along X-axis. A straight line is obtained as shown. Planck's constant is given by

    Physics-General
    General
    Physics-

    For the photoelectric effect, the maximum kinetic energy E subscript k end subscript of the emitted photoelectrons is plotted against the frequency n of the incident photons as shown in the figure. The slope of the curve gives

    For the photoelectric effect, the maximum kinetic energy E subscript k end subscript of the emitted photoelectrons is plotted against the frequency n of the incident photons as shown in the figure. The slope of the curve gives

    Physics-General
    parallel

    card img

    With Turito Academy.

    card img

    With Turito Foundation.

    card img

    Get an Expert Advice From Turito.

    Turito Academy

    card img

    With Turito Academy.

    Test Prep

    card img

    With Turito Foundation.