The shortest wavelength f X-rays emitted from an X-ray tube depends on:
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:
If you fill a glass to the brim with ice water and the ice melts, what will happen?
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
Air contains maximum amount of :
The heat required to raise the temperature of body by 1 K is called:
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.
Hubble’s law is based on the:
Which one of the following pairs is mismatched
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?
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:
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?
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:
Which polymer is used in the manufacture of paints and lacquers?
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:
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?
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:
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
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: