Sr. # | Questions | Answers Choice |
---|---|---|
1 | A bomb of mass 30 kg at rest explodes into two pieces of masses 18 kg and 12 kg. The velocity of 18 kg mass is 6 ms1 The KE of other mass is |
324 J 256 J 245 J 524 J |
2 | The power needed to lift amass of 5000g to height of 1min 2 second is | 2.45 watt 24.5 watt 245 watt 2.45 k watt |
3 | 3 joules of work is done in 3 seconds, then power is: | 6 watt 3 watt 18 watt 1 watt |
4 | A stone is thrown up from the surface of earth when it reaches at maximum height. its total energy is equal to |
mgh 1/2 𝑚𝑣<sup>2</sup> zero 2mgh |
5 | You lift a suit case from the floor and keep it on a table. The work done by you on the suitcase does not depend on |
the path taken by the suitcase weight of the suitcase initial and final position None |
6 | Car X is traveling at half the speed of car Y. Car X has twice mass of car Y. Which statement is correct? |
Car X has half the kinetic energy of car Y Car X has one quarter of the kinetic energy of car Y Car X has twice the kinetic energy of car Y The tow cars have the same kinetic energy |
7 | 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 |
8 | Beta particles have less ionizing power than that of alpha particles because: | Their smaller energy Their smaller mass Their smaller density Their smaller charge |
9 | In electron microscope, we use high speed electrons because them | Penetration power is higher Wavelength is smaller Frequency is smaller K.E is smaller |
10 | In photoelectric effect experiment, stopping potential depend upon | Intensity of light Frequency of light Photoelectric current Both A and B |
11 | 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 |
12 | Beta particles have penetration of about: | 100 times more than that of the gamma particles 100 times less than that of an alpha ray 100 times more than that of an alpha ray 10 times more than that of an alpha particle |
13 | 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 |
14 | Temperature of black body radiating at 270c is increased to 327oc, then emittedenergywill increase by | 2 times 12 times 16 times 4 times |
15 | Which row is correct for fission and for fusion? | Produces larger nuclei Produces larger nuclei Produces smaller nuclei Produces smaller nuclei |
16 | 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 |
17 | 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 |
18 | The most penetrating radiations out of the following is that of | 𝛾-rays β-rays α-particles X-rays |
19 | 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 |
20 | During a negative β-decay | An atomic electron is ejected A neutron in the nucleus decays emitting an electron An electron which already present within the nucleus is ejected A part of binding energy of nuclei is converted into electron |
21 | During a negative β-decayv | An atomic electron is ejected A neutron in the nucleus decays emitting an electron An electron which already present within the nucleus is ejected A part of binding energy of nuclei is converted into electron |
22 | 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 |
23 | When a radioactive nucleus remits a beta particle, the proton neutron ratio: | Decreases Increases Remain same None of the above |
24 | Intensity of light from a point source at the edge of unit sphere will be: | 𝑃 𝑃 P(4π) 4𝜋 |
25 | When the radioactive nucleus emits a beta particle, the proton neutron ration: | increases by one Remains same Decreases by one Decreases by four |
26 | The binding energy per nucleon is: | Greater for heavy nuclei Least for heavy nuclei Greatest for light nuclei Greatest for medium nuclei |
27 | The rate of decay radioactive substance: | Is constant Decrease exponentially with time Varies inversely with time Decrease linearly with time |
28 | Three quarks make up a: | Leptons Mesons Baryons Quark |
29 | 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 |
30 | 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 |
31 | The particles equal in mass or greater than mass of protons are called: | Leptons Mesons Baryons Quarks |
32 | 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 |
33 | In nuclear fission reaction, when the products are 140X and 94Sr, the number of neutrons emitted is | 1 2 5 9 |
34 | Because of large mass when 𝑎 −paricle enters the atom or molecule it: | Moves in zigzag path Moves along straight line Moves along circular path None of these |
35 | 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 |
36 | 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> |
37 | The fusion of hydrogen into helium is more likely to take place: | At high temperature and high pressure At high temperature and low pressure At low temperature and low pressure At low temperature and high pressure |
38 | The more readily fissionable isotope of uranium has an atomic mass of: | 220 230 235 240 |
39 | The number of electrons in a nucleus X of atomic number Z and mass number A is: | A W Z Y |
40 | The Balmer series is found in the spectrum of: | Hydrogen Nitrogen Oxygen All |