PPSC Physics Full Book With Answers

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PPSC Physics Full Book

Sr. # Questions Answers Choice
1 The mass defect of Bohr's atomic model is Exclusion of nuclear motion missing of classical and quantum theories Failed to explain the fine structure of spectral line All of the above
2 Which quantity remains fixed in isobars. Mass number Atomic number Number of neutrons Number of protons
3 Which given quantity remains the same in isotones. Mass number Atomic number Number of neutrons Number of protons
4 Photocells are used for Security systems Counting systems Automatic door system All of the above
5 In a photocell, certain metals emit electrons for Visible light X-rays Infrared light Ultraviolet light
6 In potential for the material of cathode pure metals are rarely used because of their Low reflecting power High reflecting power Low resolving power High resolving power
7 An increase in frequency above threshold frequency results in. Increase in photo electric current Increase in K.E. of electrons Decrease in photoelectric current Decreases in K.E. of electrons
8 In the experiment of photo electric effect the minimum frequency of photons at which electrons are emitted from a metal surface is called. Critical frequency Typical frequency Threshold frequency Surface frequency
9 The emission of electrons from a metal surface when exposed to light of suitable frequency is called. Pair production Compton effect Photo electric effect Zeeman effect
10 When light of particular frequency is allowed to fall upon a metal surface electrons are emitted from a these emitted electrons are called. Photons Holes Quants Photo electrons
11 The value of principal quantum number for an ionized atom is. 13.6 eV 27.2 eV 54.4 eV 100 eV
12 Isotopes are the atoms of the same elements which contain equal number of. Nucleus Neutrons Protons Electrons
13 The unit Planck's constant is equivalent to that of. Energy Force Velocity Angular momentum
14 Which of the following atom pair have the same structure. N, C B, Li H2 , Ne Li , Na
15 When of the following radiations are not emitted by electron transitions in atoms. Visible rays Ultraviolet rays Infrared radiations Alpha particles
16 The path of electron in Rutherford atomic model according to classical theory a. Parabolic Straight line Spiral Circular
17 Alpha particles are Helium nuclei sodium nuclei Ioized nuclei Hydrogen nuclei
18 The ionization potential of hydrogen atom is. 10.2 V 13.6 V 12.97 V 27.2 V
19 Bohr's atomic model assumes Nucleus is of infinite mass and is at rest electron in a quantized orbit will not radiate energy Mass of electron remains the same All of the above
20 According to Max. Planck, energy is released or absorbed in discrete packets called. quanta Meson Energy shells Position
21 When a platinum wire is heated of 1600 oC, it becomes orange Cherry red Dull red White
22 At high temperature a body generally emits redactions of. Small wavelengths Long wavelengths Moderates wavelengths Zero wavelengths
23 Mass -energy relation means that the product of mass times the square of the speed of light must be equal to. Torque Momentum Energy Impulse
24 If an object moves with velocity of light the apparent mass of the object as compared to list original mass is greater Smaller Same zero
25 If an object moves with velocity of light the apparent length of the object moving the direction of motion becomes. Larger Smaller Zero Infinity
26 When an object moves with a very high speed the length in the direction of motion. Contracts Expands Remains the same Becomes infinity
27 The part of theory of relativity which deals with accelerated bodies is called. special theory of relativity General theory of relativity Lorentz's theory of relativity Galilean theory of relativity
28 Radius of the Bother's orbit is r the radius of second orbit will be. 2 r 3 r 4 r 8 r
29 Which term given below refers to the concept moving clocks run slower than clocks at rest w.r.t an observer. Simultaneously Mass variation time dilation Length contraction
30 Which of the following describes that the time interval between two events may be different in different of references Simullaneously Time dilation Length contraction Mass variation
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