Home
Class 12
PHYSICS
If radiation of all wavelengths from ult...

If radiation of all wavelengths from ultraviolet to infrared ispassed through hydrogen gas at room temperature absorption lines will be observed in the

A

Lymann series

B

Balmer series

C

Both (A) and (B)

D

Neighter (A) nor (B)

Text Solution

Verified by Experts

The correct Answer is:
A
Room temperature `rArr n = 1` so lyman series
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • SIMPLE HARMONIC MOTION

    ALLEN |Exercise Exercise - 24|2 Videos

  • SIMPLE HARMONIC MOTION

    ALLEN |Exercise Exercise - 25|2 Videos

  • SIMPLE HARMONIC MOTION

    ALLEN |Exercise Exercise - 22|2 Videos

  • RACE

    ALLEN |Exercise Basic Maths (Wave Motion & Dopplers Effect) (Stationary waves & doppler effect, beats)|25 Videos

  • TEST PAPER

    ALLEN |Exercise PHYSICS|4 Videos

Similar Questions

Explore conceptually related problems

A beam of ultraviolet light of all wavelength passes through hydrogen gas at room temperature, in the x-direction. Assume that all photons emitted due to electron transitions inside the gas emerge in the y-direction. Let A and B denote the lights emerging from the gas in the x-and y-directions respectively. (i) Some of the incident wavelengths will be absent in A (ii) Only those wavelengths will be present in B which are absent in A (iii) B will contain some visible light (iv) B will contain some infrared light

A 12.5 eV electron beam is used to bombard gaseous hydrogen at room temperature. What series of wavelengths will be emitted?

Knowledge Check

  • If the longest wavelength of the ultraviolet region of hydrogen spectrum is lambda_(0) then the shortest wavelength of its infrared region is ......

    A
    `(46)/(7)lambda_(0)`
    B
    `(20)/(3)lambda_(0)`
    C
    `(36)/(5)lambda_(0)`
    D
    `(27)/(4)lambda_(0)`

    • Similar Questions

    Explore conceptually related problems

    A 12.5 eV electron beam is used to bombard gaseous hydrogen at room temperature. What series of wavelengths will be emitted ?

    Take some (approximately 5 g) impure sample of copper sulphate in a china dish. Dissolve it in minimum amount of water. Filter the impurities out. Evaporate water from the copper sulphate solution so as to get a saturated solution. Cover the solution with a filter paper and leave it undisturbed at room temperature to cool slowly for a day. What do you observe in the china dish ?

    When an electric discharge is passed through hydrogen gas, the hydrogen m olecu les dissociate to produce excited hydrogen atoms. These excited atom s em it electrom agnetic radiation of discrete frequencies which can be given by the general formula What points of Bohr’s model of an atom can be used to arrive at this formula ? Based on these p o in ts derive the above form ula giving description of each step and each term.

    Find the typical de Broglie wavelength associated with a He atom in helium gas at room temperature (27^(@)C) and 1 atm pressure, and compare it with the mean separation between two atoms under these conditions.

    According to Stefan's law of radiation, a black body radiates energy sigmaT^(4) from its unit surface area every second where T is the surface temperature of the black body and sigma=5.67xx10^(-8)W//m^(2)K^(4) is known as Stefan's constant. A nuclear weapon may be thought of as a ball of radius 0.5 m. When detonated, it reaches temperature of 10^(6) K and can be treated as a black body. If all this energy U is in the form of radiation, corresponding momentum is p=U/c . How much momentum per unit time does it impart on unit area at a distance of 1 km ?

    The ionization energy of hydrogen atom in the ground state is 1312 kJ "mol"^(-1) . Calculate the wavelength of radiation emitted when the electron in hydrogen atom makes a transition from n = 2 state to n = 1 state (Planck’s constant, h = 6.626 xx 10^(-34) Js , velocity of light, c = 3 xx 10^8 m s^(-1) , Avogadro’s constant, N_A = 6.0237 xx 10^23 "mol"^(-1) ).

    A point source is emitting 0.2 W of ultravio- let radiation at a wavelength of lambda = 2537 Å . This source is placed at a distance of 1.0 m from the cathode of a photoelectric cell. The cathode is made of potassium (Work function = 2.22 eV ) and has a surface area of 4 cm^(2) . (a) According to classical theory, what time of exposure to the radiation shall be required for a potassium atom to accumulate sufficient energy to eject a photoelectron. Assume that radius of each potassium atom is 2 Å and it absorbs all energy incident on it. (b) Photon flux is defined as number of light photons reaching the cathode in unit time. Calculate the photon flux. (c) Photo efficiency is defined as probability of a photon being successful in knocking out an electron from the metal surface. Calculate the saturation photocurrent in the cell assuming a photo efficiency of 0.1. (d) Find the cut – off potential difference for the cell.

    Home
    Profile