The shortest wavelength f X-rays emitted from an X-ray tube depends on:
The current the tube
Voltage applied to the tube
The nature of the gas in the tube
The atonmic number of the target material
Electrons with energy 80 keV are incident on he tungsten target of an X-ray tube. K-shell electrons of tungsten have - 72.5 contain only k.v energy. X-rays emitted by the tube:
A continuous X-ray spectrum (Br mssttrrahlung) with a minimum wavelength of ~ 155 A
A continuous X-ray spectrum (B emsstrahlung) with all wavelengths
The characteristic X-ray spectrum of tungsten
A continuous X-ray spectrum ( Bremsstrahlung) with a minimum wavelength of ~ 155 A and the characteristic X-ray spectrum of tungsten
If you fill a glass to the brim with ice water and the ice melts, what will happen?
The glass will over flow as the ice turns to water
The level of water in the glass will remain unchanged as the ice melts
The water level will drop slightly as the ice melts
I'll never find out because I'll drink the water or walk away before anything happens
How many nodes are expected for the vibrational wavefunction with quantum number v = 4?
In a multi – electron atom, which of the following orbitals described by the three quantum numbers will have the same energy in the absence of magnetic acid and electric fields? (A) n = 1, l = 0, m = 0 (B) n = 2, l = 0, m = 0 (C) n = 2, l = 1, m = 1 (D) n = 3, l = 2, m = 1 (E) n = 3, l = 2, m = 0
(A) and (B)
(B) and (C)
(C) and (D)
(D) and (E)
Air contains maximum amount of :
The heat required to raise the temperature of body by 1 K is called:
None of the above
Consider the following statements and select the correct code. Assertion (A): The main constituent of the liquefied petroleum gas is methane. Reason (R): Methane can be used directly for burning in homes and factories where it can be supplied through pipelines.
Both A and R are true, and R is the correct explanation of A
Both A and R are true, but R is not the correct explanation of A
A is true, but R is false
A is false, but R is true
Hubble’s law is based on the:
Law of gravitation
Enriched uranium is:
Uranium rods kept under special shield
Natural uranium in which the component of radioactive isotope U235 is artificial increased
Natural uranium mixed with thorium
Uranium rods coated with chromium
Which one of the following pairs is mismatched
Mass Spectrograph : Chadwick
Atomic number : Moseley
Neutron : Millikan
Measurement of charge of an electron : Aston
Consider the following statements: If there were no phenomenon of capillarity (1) It would be difficult to use a kerosene lamp. (2) One would not be able to use a straw to consume a soft drink. (3) The blotting paper would fail to function. (4) The big trees that we see around would not have grown on the earth. Which of the statements given above are correct?
1, 2 and 3 only
1, 3 and 4 only
2 and 4 only
1, 2, 3 and 4
A reaction was found to be second order with respect to the concentration of carbon monoxide. If the concentration of carbon monoxide is doubled, with everything else kept the same, the rate of reaction will:
Increase by a factor of 4
Which among the following gas was leaked at Bhopal during the Bhopal gas tragedy at 2-3 December 1984?
Consider the following statements: Hard water is not suitable for (1) Drinking (2) Washing clothes with soap (3) Use in boilers (4) Irrigating crops Which of these statements are correct?
1 and 3
2 and 3
1, 2 and 4
1, 2, 3 and 4
Natural rubber is a polymer derived from ?
Increasing order of stability among the three main conformations (i.e. Eclipse, Anti, Gauche) of 2-fluoroethanol is:
Eclipse, Gauche, Anti
Gauche, Eclipse, Anti
Eclipse, Anti, Gauche
Anti, Gauche, Eclipse
Which polymer is used in the manufacture of paints and lacquers?
Poly vinyl chloride
An amount of solid NH4HS is placed in a flask already containing ammonia gas at a certain temperature and 0.50 atm. Pressure. Ammonium hydrogen sulphide decomposes to yield NH3 and H2S gases in the flask. When the decomposition reaction reaches equilibrium, the total pressure in the flask rises to 0.84 atm. The equilibrium constant for NH4HS decomposition at this temperature is:
Which one is an organic Acid ?
An electron changes its position from n= 2 to the or bit n = 4 of an atom. The wave length of the emitted radiations is (R = Rydberg’s constant)
When soggy biscuits are kept inside the fridge for sometime they become crisp because:
Cooling releases extra moisture
Humidity inside the fridge is low and extra moisture is absorbed
Humidity inside the fridge is high and extra moisture is absorbed
Pressure inside the fridge is high and helps in releasing extra moisture
The atoms in a molecule are joined together by ____________.
Which of the following factors is of no significance for roasting sulphide ores to the oxides and not subjecting the sulphide ores to carbon reduction directly?
Metal sulphides are thermodynamically more stable than CS2
CO2 is thermodynamically more stable than CS2
Metal sulphides are less stable than the corresponding oxides
CO2 is more volatile than CS2
Alloys made with mercury as one metal are called ?
Amount of oxalic acid present in a solution can be determined by its titration with KMnO4 solution in the presence of H2SO4. The titration gives unsatisfactory result when carried out in the presence of HCl, because HCl:
Gets oxidised by oxalic acid to chlorine
Furnishes H+ ions in addition to those from oxalic acid
Reduces permanganate to Mn2+
Oxidises oxalic acid to carbon dioxide and water
The chemical used as a fixer in photography is ?
The half-life period of a rdaioactive element X is same as the mean life time of another radioactive element Y. Initially both of them have the same number of atoms. Then
X and Y have the same decay rate inittially
X and Y decay at the same rate always
Y will decay at a faster rate than X
X will decay at a faste rate than Y
Two solutions of a substance (non electrolyte) are mixed in the following manner. 480 ml of 1.5 M first solution + 520 mL of 1.2 M second solution. What is the molarity of the final mixture?
On a pressure-temperature phase diagram, the conditions under which a one-component system exists as two phases in equilibrium corresponds to:
The entire diagram
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