MDCAT Physics Chapter 12 Atomic spectra Induction Online Test With Answers

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MDCAT Physics Chapter 12 Atomic spectra Induction Online Test

Sr. # Questions Answers Choice
1 Light of frequency 2 times the threshold frequency is incident on the metalsurface. Ifthe frequency is by quartered and intensity is doubled, the photoelectric becomes Quadrupled Zero Doubled Halved
2 In electron microscope, we use high speed electrons because them Penetration power is higher Wavelength is smaller Frequency is smaller K.E is smaller
3 In photoelectric effect experiment, stopping potential depend upon Intensity of light Frequency of light Photoelectric current Both A and B
4 de-Broglie wavelength associated with an electron moving at a speed of 1x106 ms-1 is 4x10-10 ms-1 5x10-10 m 6x10-10 m 7x10-10 m
5 If an electron is accelerated such that its K.E is 4 times of its rest mass energythen thetotal relativistic energy of electrons is about 5 × 10–12 J 4 × 10–13 J 3 × 10–13 J 6 × 10–12 J
6 Temperature of black body radiating at 270c is increased to 327oc, then emittedenergywill increase by 2 times 12 times 16 times 4 times
7 A photo cell receives light from a source at 50 cm away and produces 40mAcurrent inthe circuit. When the same source at is at distance 1 m from photo cell,current in the circuit will be 20 mA 80mA 60 mA 10 mA
8 Work function of all metals varies from 2 eV to 4eV. It is 4.2 eV for Aluminum and2eV for Sodium. If these two metals are illuminated by same light, the thresholdfrequency ofAluminum is Less than Sodium Equal to that of Sodium Grater than Sodium Can’t be decided
9 Choose incorrect about properties of photon Rest mass of photon is zero A photon is never at rest Photon is not deflected by electric field not by magnetic field The velocity of photon is different in different media
10 In photo electric cell, the photo electric current Decreases with increase in frequency of light Depends on intensity and frequency of light Does not depend upon the frequency of light and but depends upon intensity of light Increases with increase in frequency of light
11 Intensity of light from a point source at the edge of unit sphere will be: 𝑃 𝑃 P(4π) 4𝜋
12
Monochromatic light of wavelength 300 nm is incident normally on a surface of area 4 cm2.
If the intensity of light is 150 mW/m2; the rate at which photon strike the surface:
 2.53 × 1019 7.5 × 1019 9.1 × 1013 2.53 × 1013
13 How many photons per second does a one-watt bulb emit if its efficiency is 10% and the wavelength of light is 500 nm: 2.53 × 1017 2.53 × 1019 7.5 × 1019 7.5 × 1017
14 What will be the number of photons emitted per second by 25 W source of monochromatic light of wavelength 600 nm: 7.5 × 1017 7.5 × 1019 5.5 × 1019 5.5 × 1017
15 What is the momentum of a photon of light of wavelength 500 nm in kgm/s: 1.32 × 10−21 1.32 × 10−23 1.32 × 10−25 1.32 × 10−27
16 Which one is the correct express of de-Broglie equation for the length of atoms of mass m at temp? T(k=Boltzmann’s constant): <br>
17 The Balmer series is found in the spectrum of: Hydrogen Nitrogen Oxygen All
18 When an electron in an atom goes from a lower to higher its: K.E. increases, P.E. decreases K.E. increases P.E increases K.E. decrease, P.E. increases
19 The shortest wavelength of X-rays emitted from an X-rays tube depends on the: Current in the tube Voltage applied to the tube Nature of gas in the tube Nature of material of tube
20 For X-rays which of the following is not correct: Cause of ionization in air when they pass through it Can be deflected by electric and magnetic fields Can be used to detect flaws in metal casting Travel with the speed of light
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