Solved Past Papers MCQs of MDCAT for the preparation of Medical and Dental College Admission Test and other medical tests.
Q.26 In Helium-Neon laser, population inversion of _________ atoms is achieved which emit radiations, when they are stimulated to fall at lower level.
A) Neon C) Helium and Neon
B) Helium D) Chromium
Q.27 The SI unit of absorbed dose ‘D’ i.e. radiation effect is Gray and one Gray is equal to
A) kJ / mol C) kg / J
B) J / mol D) J / kg
Q.28 If the number of turns of a solenoid circular coil is doubled, but the current in the coil and radius of the coil remains same, then what will be the magnetic flux density produced by the coil?
A) Magnetic flux density will be halved
B) Magnetic flux density increases by different amount at different points
C) Magnetic flux density remains unchanged
D) Magnetic flux density will be doubled
Q.29 Which of the following lights travels the fastest in optical fibres?
A) Visible light. C) Ultra-violet.
B) Invisible infra-red. D) Ordinary light.
Q.30 The algebraic sum of potential changes in a closed circuit is zero is Kirchhoff’s __________ rule.
A) First. C) Third.
B) Second. D) None of these.
Q.31 Wavelength of X-rays is the order of:
A) 10-6 m C) 10-13 m
B) 10-10 m D) 100 m
Q.32 Laser beam can be used to generate three-dimensional image of object in a process called:
A) Computed technology C) Holography
B) Computed tomography D) Computerized axial tomography
Q.33 Which of the following is true for Lasers?
A) Electrons are emitted C) Coherent monochromatic light is emitted
B) Stimulated emission of electrons is needed D) There is a population inversion of photons
Q.34 The minimum distance from the eye at which an object appears to be distant is:
A) 25 cm C) 35 cm
B) 22 cm D) 20 cm
Q.35 What is meant by spontaneous emission of electrons in solids?
A) Electrons being emitted by the solids through photoelectric effect when irradiated with electromagnetic radiation
B) Incident electrons colliding with electrons in solids and releasing doubling the number of incident electrons
C) Electrons in solids are emitted without any external stimulus through radiation
D) Excited electrons going back to lower energy states immediately by releasing energy.
Q.36 When electrons lose all their kinetic energy in the first collision, the entire kinetic appears as an X-ray photon of energy:
A) K.E = eV C) K.E =hc/λmin
B) K.E =hλmin/c D) K.E =h/λmax
Q.37 The characteristic X-ray spectrum is due to:
A) The absorption of neutrons by target material C) The bombardment of target material by electrons
B) The bombardment of target material by protons D) The bombardment of target material by alpha particles
Q.38 Ionizing capability of gamma rays is:
A) Equal to alpha and beta particle C) Less than both alpha and beta particles
B) Less than alpha but greater than beta particles D) Less than beta but greater than alpha particles
Q.39 Half-life of a radioactive element is:
A) Inversely proportional to square of decay constant C) Directly proportional to decay constant
B) Directly proportional to square of decay constant D) Inversely proportional to decay constant
Q.40 The transformation of a neutron into proton in the nucleus gives rise to emission of:
A) Beta particles C) Gamma particles
B) Alpha particles D) X-rays
Q.41 The ratio of the rate of decay of a parent atom to the number of radioactive nuclei present at that time is equal to:
A) Half-life of radioactive element C) Decay constant of radioactive element
B) Mean life D) Activity if radioactive element
Q.42 Which one of the following particle is emitted as a result of nuclear reaction?
Ra226 → Rn222
A) Beta C) Gamma rays
B) Alpha D) One alpha and one beta
Q.43 Which of following is used to estimate the circulation of blood in a patient?
A) Carbon-14 C) Phosphorus-32
B) Carbon-12 D) Sodium-24
Q.44 For the radiotherapy of a patient, it is required to double the absorbed dose in gray. What step must be taken?
A) Energy must be quadrated C) Energy must be raised four times
B) Energy must be halved D) Energy must be doubled
CHEMISTRY
Q.45 In mass spectrometer, detector or collector measures the:
A) Masses of isotopes C) Relative abundances of isotopes
B) Percentages of isotopes D) Mass numbers of isotopes
Q.46 How many ‘Cl’ (chlorine) atoms are in two moles of chlorine?
A) 2 × 6.02 × 10ˉ23 atoms C) 2 × 1023 atoms
B) 35.5 × 6.02 × 1023 atoms D) 2 × 6.02 × 1023 atoms
Q.47 Melting point of water is higher than petrol, because intermolecular forces in water are:
A) Weaker than petrol C) Same as in petrol
B) Stronger than petrol D) Negligible
Q.48 DNA molecule is double stranded, in which two chains of DNA are twisted around each other by:
A) Hydrogen bonds C) Covalent bonds
B) Vander Waal’s force D) Dative bonds
Q.49 The elements for which the value of ionization energy is low, can:
A) Gain electrons readily C) Loss electrons less readily
B) Gains electron with difficulty D) Lose electrons readily
Q.50 The nature of cathode rays in discharge tube:
A) Depends on the nature of gas taken in the discharge tube
B) Depends upon the nature of cathode in discharge tube
C) Is independent of the nature pf the gas in discharge tube
D) Depends upon the nature of anode in the discharge tube
READ MORE:
- Solved Past Papers MCQs of MDCAT 1
- Solved Past Papers MCQs of MDCAT 2
- Solved Past Papers MCQs of MDCAT 3
