Please wait...
/
-
Let 'M' be the mass and 'L' be the length of a thin uniform rod. In first case, axis of rotation is passing through centre and perpendicular to the length of the rod. In second case axis of rotation is passing through one end and perpendicular to the length of the rod. The ratio of radius of gyration in first case to second case is
Verify mobile number to view the solution
Two parallel plate air capacitors of same capacity C are connected in series to a battery of emf E. Then one of the capacitors is completely filled with dielectric material of constant K. The change in the effective capacity of the series combination is
If the density of air is ρa and that of the liquid ρl, then for a given piston speed the rate (volume per unit time) at which the liquid is sprayed will be proportional to
A ball is thrown vertically upwards. Which of the following plots represents the speed-time graph of the ball during its flight if the air resistance is not ignored ?
Calculation:
Given air resistance is not ignored. Taking downward as positive y direction.
Equation of motion for upward motion,
Solving the equation gives us an exponential function i.e a function which is not linear
Hence, the fourth graph is most appropriate.
If uncertainty in position and momentum are equal, then uncertainty in velocity is
Concept:
Heisenberg’s Uncertainty Principle:
Directions For Questions
Match List I with List II:
...view full instructions
Choose the correct answer from the options given below:
CONCEPT:
Identification of Functional Groups
EXPLANATION:
(A) Fehling’s solution is used to distinguish between aldehyde and ketone functional groups. Aldehydes oxidize to give a positive result but ketones won’t react to the test (except for a-hydroxy ketones). Fehling’s test is used as a general test for determining monosaccharides and other reducing sugars.
(C) This reaction is a chemical test for detection of primary amines, in which the amine is heated with alcoholic potassium hydroxide and chloroform. If a primary amine is present, the isocyanide is formed. The reaction is known as carbylamine reaction.
RNH2 + CHCl3 + 3KOH → RN+ ≡ C– + 3KCl + 3H2O
When a methyl ketone (even acetaldehyde) is reacted with halogen in aqueous sodium hydroxide, the ketone gets oxidised to the sodium salt of acid with one carbon less than ketone and at the same time haloform (CHX3) also gets formed.
The hydroxide ion acts as a nucleophile and attacks the electrophilic carbon which is doubly bonded to oxygen. This carbon-oxygen double bond becomes a single bond making the oxygen atom anionic.
0.1 mole of CH3NH2 (pKb = 3.3010) is mixed with 0.08 mol of HCl and volume is made to 1 litre. The pH of solution is:
Correct answer: 3)
Explanation:
CH2NH2(base) on reaction with HCl to give salt of a weak base and strong acid as CH3NH3+Cl-.
A tangent is drawn to the parabola y2 = 6x which is perpendicular to the line 2x + y = 1. Which of the following points does NOT lie on it?
⇒ x - 2y + 6 = 0
We know that if a point is lying on a line, it will satisfy the equation of that line.
Except point (5,4), all the points (0,3),(-6,0) and (4,5) are lying on the line x-2y+6=0.
Therefore, the correct answer is (5,4).
Correct (-)
Wrong (-)
Skipped (-)