MDCAT Physics MCQ's Test With Answers

MDCAT Physics MCQ's Test

Sr. # Questions Answers Choice
1 Photo cells are used for : Security and counting system Automatic door system Automatic street lighting All of these
2 In a photocell, certain metal emits electrons for : Visible light Infrared light Ultraviolet light All of these
3 In a photocell, cesium coated oxidized silver emits electrons for : Visible light Infrared light Ultraviolet light All of these
4 In a photocell, sodium and potassium emit electrons for: Visible light Infrared light Ultraviolet light All of these
5 A photo cell is based on: Compton effect Pair production Photo cell All of these
6 The maximum kinetic energy of emitted photoelectrons depends upon: The intensity of incident light Frequency of the incident light Temperature of the surface All of above
7 The minimum energy required by an electron to eject from metal surface is known as: Photo energy Critical energy Threshold energy Work function
8 In photoelectric effect, electrons are emitted: Slowly Intermittently Both (a) & (b) Instantly
9 In photoelectric effect, electrons are emitted with: Same energy Different energies Both (a) & (b) Intermittent energies
10 The photoelectric effect was explained by: Einstein Davison Hertz Planck
11 The stopping potential for a certain metal is 10 volt, the max. Energy of emitted electron is: 10 J 100 J 1.6 × 10-18 J 1.6 × 10-19 J
12 There is a certain frequency below which no electrons are emitted from the metal surface, this frequency is known as: Critical frequency Threshold frequency Maximum frequency Minimum frequency
13 The maximum energy of the photoelectrons depends upon: Frequency of incident light Intensity of incident light Nature of metal Both (a) & (c)
14 The maximum energy of the photoelectrons can be determined by making the: Anode positive Anode negative Cathode positive Both (b) & (c)
15 Moving photons posses: Energy Momentum Wavelength All of these
16 A human eye can detect the electromagnetic radiations of the type: Infrared radiations For- infrared radiations X-rays radiations Red radiations
17 A human eye can detect the electromagnetic radiations of the type: Infrared radiations For- infrared radiations X-rays radiations Red radiations
18 The energy of photon of wavelength 620 nm is: 0.5 eV 1.0 eV 1.5 eV 2.0 eV
19 The energy of photon of energy 1 eV is: 1240 nm 1040 nm 1000 nm 620 nm
20 The energy of photon of wavelength 1240 nm is: 0.5 eV 1.0 eV 1.5 eV 2.0 eV
21 Joule-second is the unit of: Energy Heat Planck’s constant None of these
22 The dimensions of Planck’s constant “h” are same as that of: Momentum Angular momentum Work Torque
23 In full wave rectification by bridge the number of diodes required are 3 4 2 5
24 The diodes works on A.C D.C both A and B None of these
25 The unit of gain (G) for non-inverting amplifier is Ampere ohm Volt None of these
26 The simplest type of rectification known as half wave rectification is obtained by Using a transistor Suppressing the harmonics in A.C. voltage Suppressing half wave of A.C. supply by using diode Using a Coolidge
27 Inverting amplifier circuits have A very high input impendance A very low input impendance A low output impendance Both A and C
28 In full wave rectification, the output D.C. voltage across the load is obtainedfor The positive half cycle of input A.C. (C) The complete cycle of input A.C. The negative half cycle of input A.C. The complete cycle of All of the above
29 The method by which only one half of A.C cycle is converted into direct current is called half wave amplification half wave rectification Full wave rectification full wave amplification
30 In a full wave rectifier, the diode conducts during Both halves of the input cycle A portion of the positive half cycle of the input Positive half cycle of the input Positive half cycle of the input Both halves of the input cycle
31 A diode characteristics curve is a graph plotted between; Current and time Voltage and time Voltage and current Forward voltage and reverse current
32 Gain of operational amplifier is independent of; Internal structure External Structure Batteries Potential changes
33 The junction potential for Germanium is; 3v 0.3 v 7v 0.7 v
34 A PN junction diode cannot be use: As rectifier For converting light energy to electrical energy For getting light radiation For increasing the amplitude of an ac signal
35 In a half wave rectifier circuit operating from 50 Hz mains frequency, the fundamental frequency in the ripple would be: 25 Hz 70.7 Hz 50 Hz 100 Hz
36 A diode as a rectifier converts: A)c into D)c D)c into A)c Varying D)c current into constant D)c current High voltage into low voltage and vice-versa
37 For full wave rectification, the minimum number of diodes used is: 1 2 3 4
38 A pure semiconductor has: An infinite resistance at 0<sup>o</sup>C) A finite resistance which does not depend upon temperature A finite resistance which decreases with temperature A finite resistance which increase with temperature
39 When two semiconductors of p- and n-type are brought into contact, they from a p-n junction which act like a: Conductor Amplifier Oscillator Rectifier
40 The diode charactristics curve is plot between I &amp; t V&amp; t V&amp; I None
Download This Set

Is this page helpful?