The radiation corresponding to 3 → 2 transition of a hydrogen atom falls on a gold surface to generate photoelectrons. These electrons are passed through a magnetic field of 5 × 10-4 T. Assume that the radius of the largest circular path followed by these electrons is 7 mm, the work function of the metal is:
(Mass of electron = 9.1 × 10-31 kg)
If ge and gm are the accelerations due to gravity on the surface of the earth and the moon respectively and if Millikan's oil drop experiment could be performed on the two surfaces, one will find the ratio to be;
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The ratio of mass densities of nuclei of 40Ca and 16O is close to
Radiation of two photon energies twice and five times the work function of metal are incident sucessively on the metal surface. The ratio of the maximum velocity of photoelectrons emitted is the two cases will be
The self inductance of an electric fan motor is 10 H. In order to impart maximum power at 50 Hz, it should be connected to a capacitance of
The figure gives experimentally measured B vs. H variation in a ferromagnetic material. The retentivity, co-ercivity and saturation, respectively, of the material are:
A block of mass 200 g is kept stationary on a smooth inclined plane by applying a minimum horizontal force F = N as shown in figure.
The value of x = ________.
A ray of light is incident at an angle of incidence 60° on the glass slab of refractive index √3. After refraction, the light ray emerges out from other parallel faces and lateral shift between incident ray and emergent ray is 4√3cm. The thickness of the glass slab is ______ cm. (In integers)
For a reaction at equilibrium
the relation between dissociation constant (K), degree of dissociation (∞) and equilibrium pressure (p) is given by:
Given below are the oxides:
Na2O, As2O3, N2O, NO and Cl2O7
The number of amphoteric oxides is:
Spin-only magnetic moment of an octahedral complex of Fe2+ in the presence of a strong field ligand in B.M. is
An aqueous solution of NiCl2 was heated with excess sodium cyanide in presence of strong oxidizing agent to form [Ni (CN)6]2-. The total change in number of unpaired electrons on metal centre is _________.
When 200 mL of 0.2 M acetic acid is shaken with 0.6 g of wood charcoal, the final concentration of acetic acid after adsorption is 0.1 M. The mass of acetic acid adsorbed per gram of carbon is ________ g. (In integers)
Consider the above reaction. The number of π electrons present in the product 'P' is _________. (In integers)
A solution of Fe2(SO4)3 is electrolyzed for 'x' min with a current of 1.5 A to deposit 0.3482 g of Fe. The value of x is _______. [nearest integer]
Given: 1 F = 96,500 C mol-1
Atomic mass of Fe = 56 g mol-1
For the reaction at 298 K: 2A +B → C
ΔH = 400 J mol−1; ΔS = 0.2 JK−1mol−1
Determine the temperature at which the reaction would be spontaneous.
The set of all values of k for which (tan-1x)3 + (cot-1x)3 = kπ3, x ∈ R, is the interval:
Consider the line L given by the equation . Let Q be the mirror image of the point (2, 3, -1) with respect to L. Let a plane P be such that it passes through Q, and the line L is perpendicular to P. Then which of the following points is on the plane P?
Let f(x) be a polynomial function such that f(x) + f'(x) + f''(x) = x5 + 64 and fv(x) = 120. Then, the value of
If a random variable X follows the Binomial distribution B(33, p) such that 3P(X = 0) = P(X = 1), then the value of is equal to:
Let x2 + y2 + Ax + By + C = 0 be a circle passing through (0, 6) and touching the parabola y = x2 at (2, 4). Then A + C is equal to _______.
The line y = x + 1 meets the ellipse at two points P and Q. If r is the radius of the circle with PQ as diameter, then (3r)2 is equal to:
Let two points be A(1, -1) and B(0, 2). If a point P(x', y') be such that the area of ΔPAB = 5 sq. units and it lies on the line 3x + y - 4λ = 0, then a value of λ is
A random variable X has the following probability distribution:
The value of P(1 < X < 4 | X ≤ 2) is equal to:
Let f: R → R be a function defined by . If the function g(x) = f(f(f(x))) + f(f(x)), the greatest integer less than or equal to g(1) is ________ .
The number of values of θ ∈ (0, π) for which the system of linear equations
x + 3y + 7z = 0
-x + 4y + 7z = 0
(sin 3θ)x + (cos 2θ) y + 2z = 0
has a non-trivial solution, is______.
Which one of the following numbers is like the given numbers 143, 275, and 495?
A sheep is tied by two ropes, each 15 metres long, to two points P and Q 20 metres apart. Which one of the following shaded regions illustrate the region over which the sheep can move?
Directions: Read the passage and answer the question that follows:
Wetlands are indeed the vital link between water and land. It is the collective term for marshes, swamps, and bogs, found along the edges of streams, rivers, lakes and coastlines. Wetlands can be found in nearly every country and climatic zone. Indeed, wetlands are found from the Tundra to the Tropics and on every continent. They are so varied. Some are wet all the time. Some wetlands are large and some are very small. Many have been altered by human activities such as farming, building of roads, dams and towns. Wetlands are regarded wastelands sources of mosquitoes, flies, snakes and diseases. People had negative views about them and they eliminated them. Original wetlands have been destroyed; some of them have been converted into farmland, some others filled by industrial wastes.
Wetlands vary widely because of topography, climate, hydrology, water chemistry and vegetation. Wetlands are the coastal mangrove forests, lake marshes and seasonally flooded lands along river courses. Palm swamps, sea grass beds, salt flats, and coral reefs are common wetlands. They are of two types: tidal wetlands and non-tidal (inland) wetlands. Tidal wetlands are found along the Atlantic, Pacific, Alaskan and Gulf Coasts. The salt water and fluctuating water levels create a difficult environment. Some plants have adapted to the environment of saline conditions. Inland wetlands are common in the margins of lakes and rivers. They include wet meadows dominated by herbaceous plants, swamps and shrubs and tall trees. The prolonged presence of water favours the growth of specially adapted plants.
States and tribes play a critical role in the protection and management of wetlands. With the growth of education, people have started understanding ecological processes and their attitudes towards wetlands have changed. They have recognised the ecological significance of the wetlands, which are a source of valuable natural wealth. They help regulate water levels within watersheds; reduce flood and storm damages; and provide fish and wildlife habitat. They support hunting, fishing and other recreational activities.
Wetlands are the most productive ecosystems in the world. They have been described as biological supermarkets as they provide great volumes of food and attract many animal species. A variety of insects, amphibians, reptiles, birds, fish and mammals are found in these wetlands. Many species of birds, animals, rely on wetlands for food, water and shelter. The microbes, insects and wildlife are part of global cycles for water, nitrogen, and sulphur. They store carbon within their plant communities, and thus, help to moderate climate conditions.
Q. Wetlands are a source of
Directions: In the following question, a sentence has been given in direct/indirect speech. Out of the four alternatives suggested, select the one which best expresses the same sentence in indirect/direct speech.
David said to Anna, "Mona will leave for her native place tomorrow."