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In the reaction N₃ ^– + H₂O → HN₃ + OH^– , the Bronsted-Lowry base is N₃^-.

(B) proton acceptor.

(C) Dissociation is the process by which Arrhenius acids produce H⁺ ions in solution.

Magnesium ribbon should be cleaned before burning it in air to remove the oxide layer from it which may prevent or slow down the burning of magnesium ribbon.

A single alpha particle, ejected at high speed from a nucleus, can create up to 100,000 ions along its path before it gains two electrons to become a neutral helium atom. In air, an alpha particle travels about 4 cm before gaining the two electrons.

Alpha particles are released by high mass, proton rich unstable nuclei. The alpha particle is a helium nucleus; it consists of two protons and two neutrons. It contains no electrons to balance the two positively charged protons.

Principle: When current (I ) is passed in the coil, torque τ acts on the coil, given by τ = NIABsinθ 

where θ is the angle between the normal to plane of coil and the magnetic field of strength B, N is the number of turns in a coil. 

When the magnetic field is radial, as in the case of cylindrical pole pieces and soft iron core, then in every position of coil the plane of the coil, is parallel to the magnetic field lines, so that θ = 90° and sin 90° =1 

Deflecting torque, τ = NIAB 

A galvanometer cannot be used as such to measure current due to following two reasons. 

(i) A galvanometer has a finite large resistance and is connected in series in the circuit, so it will increase the resistance of circuit and hence change the value of current in the circuit. 

(ii) A galvanometer is a very sensitive device, it gives a full scale deflection for the current of the order of microampere, hence if connected as such it will not measure current of the order of ampere. 

Current sensitivity of galvanometer depends on 

(i) Number of turns N: It increases with increase of number of turns. 

(ii) Area of coil A: It increases with increase of area of coil. 

(iii) Strength of magnetic poles (B): It increases with increase of strength of poles.

(iv) Torsional rigidity of suspension: It increases with decrease of torsional rigidity of suspension.

Microwaves are produced by special vacuum tubes, namely, klystrons, Gunn diodes, magnetrons, etc.

Energy losses in a transformer are due to 

(i) Flux leakage 

(ii) Joule heating in resistance of winding 

(iii) Eddy currents 

(iv) Hysteresis

Current in 2Ω resistor is 3A 

V_A + 3 + 3 × 2 – 6 = V_B 

=> V_B =V_A +3 = 0 +3 =3V

Current in 2Ω resistor, I = 2A 

Applying Kirchhoff’s law along the path ACDB 

V_A + 2 + 2 x 2 - 4 = V_B 

=> V_B =V_A + 2 = 0 + 2 = 2V

Working of a transformer is based on the principle of mutual induction. Transformer cannot step up or step down a dc voltage. 

Reason: No change in magnetic flux. 

Explanation: When dc voltage source is applied across a primary coil of a transformer, the current in primary coil remains same, so there is no change in magnetic flux and hence no voltage is induced across the secondary coil

X-rays are produced by sudden deceleration or acceleration of electrons./In an X-ray tube.

In single slit diffraction experiment fringe width is

β = 2λD/d

If d is doubled, the width of central maxima is halved. Thus size of central maxima is reduced to half. Intensity of diffraction pattern varies square of slit width. So, when the slit gets double, it makes the intensity four times.
Thus electron has greater de Broglie wavelength, if accelerated with same speed.

The function of receiver is to receive the modulated wave and it demodulates, amplifies and reproduces the original message signal from it.

de Broglie wavelength (λ) is given as
λ = h/mv
Given v_p =v_e
where v_p = velocity of proton
v_e = velocity of electron
Since m_p > m_e
From the given relation
λ ∝1/m, hence λ_p < λ_e
Thus, electron has greater de Broglie wavelength, if accelerated with same speed.

(i) In the detection of fracture, deformity of the bones/skeletal system.
(ii) In study of crystal structure.

(i) Elements of earth’s magnetic field: 

(a) Angle of declination (θ) 

(b) Angle of dip (δ) 

(c) Horizontal component of earth’s magnetic field (B_H) 

(ii) At equator

Dipole moment P =5 x10^-4Cm.
Electric field (E) =10⁴N/C
At stable equilibrium θ₁ = 0°
At unstable equilibrium θ₂ =180°
Work done = - PE (cosθ₂ - cosθ₁)
= -(5 x 10^-8 ) (10⁴ ) (cos180 - cos0)
=10 x10^-4J

T- lymphocytes are released from thymus. T-cells help B-cells to produce antibodies and provide cell-mediated immunity.

(a) Resistance = 47kΩ ±10% = 47 x 10^-3Ω% 

Sequence of colour should be: 

Yellow, Violet, Orange and Silver 

(b) (i) Very low temperature coefficient of resistance. 

(ii) High resistivity

(i) Nuclear forces are short range attractive forces. 

(ii) Nuclear forces are charge - independent.

(i) When forward biased, the width of depletion layer decreases. 

(ii) When reverse biased, the width of depletion layer increases.

Characteristic properties of nuclear forces are :
(i) Nuclear forces are strongest forces in nature :
Magnitude of nuclear forces is 100 times that of electrostatic force and 10 times the gravitational force.
(ii) Nuclear forces are charge independent :
Nuclear forces between a pair of protons, a pair of neutrons or a pair of neutron and proton act with same strength.

Stopping potential is the minimum negative (retarding) potential of anode for which photocurrent stops or becomes zero. It is denoted by V_s. The value of stopping potential is different for different metals but it is independent of the intensity of incident light.

(i) Reverse biased :
Potential drop across the junction increases and diffusion of holes and electrons across the junction decreases. It makes the width of the depletion layer larger.
(ii) Forward biased :
Potential drop across the junction decreases and diffusion of holes and electrons across the junction increases. It makes the width of the depletion layer smaller.

Eddy currents: When a metallic plate is placed in a time varying magnetic field, the magnetic flux linked with the plate changes, the induced currents are set up in the plate; these currents are called eddy currents. These currents are sometimes so strong, that the metallic plate becomes red hot. In transformer frames there is a huge loss of energy due to production of eddy currents, so these currents are undesirable in transformer. 

Application of Eddy Currents: 

1. Induction Furnace: In induction furnance, the metal to be heated is placed in a rapidly varying magnetic field produced by high frequency alternating current. Strong eddy currents are set up in the metal produce so much heat that the metal melts. This process is used in extracting a metal from its ore. The arrangement of heating the metal by means of strong induced currents is called the induction furnace. 

2. Induction Motor: The eddy currents may be used to rotate the rotor. Its principle is: When a metallic cylinder (or rotor) is placed in a rotating magnetic field, eddy currents are produced in it. According to Lenz’s law, these currents tend to reduce to relative motion between the cylinder and the field. The cylinder, therefore, begins to rotate in the direction of the field. This is the principle of induction motion.

(a) The energy of photon of wavelength (275nm) in terms of eV can be given as

The energy of photon in transition B ΔE =[0eV-(-4.5eV]= 4.5eV. 

Hence transition ‘B’ is possible. 

(b) The wavelength of the photon in a transition is given by λ = λ_c/ΔE 

(i) Maximum wavelength of photon is possible for transition having minimum ΔE, so transition ‘A’ is possible with ΔE= 2eV. 

(ii) Minimum wavelength of the photon is possible for transition having maximum energy difference. So transition D is possible with ΔE= 10eV.

(a) If a charge particle oscillate with some frequency, produces an oscillating electric field in space, which produces an oscillating magnetic field, which inturn, is a source of electric field, and so on. Thus oscillating electric fields and magnetic fields regenerate each other, and an electromagnetic wave propagates in the space. 

(b) In microwave oven, the frequency of the microwaves is selected to match the resonant frequency of water molecules so that energy from the waves get transferred efficiently to the kinetic energy of the molecules. This kinetic energy raises the temperature of any food containing water.

(c) Microwaves are short wavelength radio waves, with frequency of order of GHz. Due to short wavelength, they have high penetrating power with respect to atmsophere and less diffraction in the atmospheric layers. So these waves are suitable for the radar systems used in aircraft navigation.

Infrared rays produced by hot bodies and molecules. These waves are used for long distance photography and for therapeutic purposes.

In fact the number of protons and number of neutrons are same before and after a nuclear reaction, but the binding energies of nuclei present before and after a nuclear reaction are different. This difference is called the mass defect. This mass defect appears as energy of reaction. In this sense a nuclear reaction is an example of mass-energy interconversion.

Working of meter bridge is based on Wheatstone bridge. The error may be minimised by taking balancing length near the middle of the bridge

(E) no correct response

C) methionine and cysteine

Some of the main threats to biodiversity are: 

1. Habitat loss and deforestation, 2. Climate change, 3. Overexploitation of resources, 4. Environmental pollution, 5. Invasive species.

1. Habitat loss and deforestation: The dramatic alteration of habitats directly threatens biodiversity. When such habitats are lost due to deforestation and other anthropogenic activities such as mining, the respective environments are unable to provide shelter, food, water, or breeding grounds for the living organisms.

2. Climate change: The global climatic changes throughout the history of the plant have definitely modified life and ecosystems in the planet. As an outcome, crucial habitats have been destroyed and a number of species have gone extinct with a huge majority at the verge of extinction. It therefore means that if the global temperatures continue to change drastically, especially due to anthropogenic activities that accelerate the process, the threats to biodiversity will continue to expand as ecosystems and species will not be able to adapt.

3. Overexploitation of resources: On the account of the ever rising human population, there has been a correlational increase in demand for manufactured products, essential goods and services. The high demands of these things have resulted in overfishing, overhunting, over-harvesting and excessive mineral resource extraction which has highly contributed to biodiversity loss. Mineral extraction, poaching, excessive logging and other forms of resource exploitation for profit has heightened the risks of species extinction. It has also altered natural habits therefore destroying food chains and interfering with the ecological balance.

4. Environmental pollution: Pollution has continued to harm the biosphere by releasing and depositing toxic chemicals into the atmospheric, terrestrial and marine systems. With the high levels of pollution every year, it is gradually disrupting the Earth’s ecosystems as the chemicals released potentially influences species’ habits and ecosystems. Pollution has also depleted ozone levels, created dead zones in marine habitats due to toxicity and acid rains, altered species feeding and breading habits, and even caused the death of many species due to oil spills or the consumption of plastic and other toxic substances.

5. Invasive species: Invasive species are the non-native species that invade normal and healthy ecosystems and threaten the survival of the native species either by attacking them or competing for the habitat’s resources. Accordingly, they upset the native biota and ecosystems thereby causing extinctions and massive threats to biodiversity.

This statement is absolutely true because it is necessary to protect forest by means of conserving air, soil and water.

Forests are a very high danger of us and if we continue to cut them for the benefit of man kind... it will surely result in further disasters by giving rise to global warming and other such problems like the average rise in the temperature of the earth giving rise to heat which is not good for us etc.

Now returning to your question what we will find is that to protect forest is increasingly being synonymous to conserving the air, our soil and of course water too.

Air:- we all must be knowing that plants need oxygen to grow and flourish further... if they get their oxygen requirement through the air and if it gets polluted, plants will not be able to breathe properly and hence they will die ultimately. and if this happens to a mass extent, this will get your forests to erode further
....

Soil:- soil is extremely necessary for as the nutrient medium of all plants since it is fully solved that the plants get their usual nitrogen and a little amount of the oxygen content for sustainable growth... if the soil gets polluted and soil pollution takes place in action what will happen if may be disastrous for the forest.

Water:- water is one of the most vital resources for for us to grow higher, if the water content in these plants is last dance with the ultimate Lee and there is obvious reasons for this.

A threatened species is one that is likely to become an endangered species in the near future throughout all or a significant portion of its range. It may be a species of animal, plant, etc. that is susceptible to endangerment in the foreseeable future. One way to identify a threatened species is through population dynamics measure of critical depensation. 

Human activities like deforestation, hunting increases the risk of extinction of animals.

1. Learn about endangered species in your area. 

2. Visit a national wildlife refuge, park or other open space.

3. Make your home wildlife friendly. 

4. Native plants provide food and shelter for native wildlife.

5. Herbicides and pesticides may keep yards looking nice but they are in fact hazardous pollutants that affect wildlife at many levels.

6. Never purchase products made from threatened or endangered species.

7. Harassing wildlife is cruel and illegal.

8. Protect wildlife habitat.

'Red Data Book' provides information on threatened species.

A Red Data Book contains lists of all the species whose continued existence is threatened. Species are classified into different categories of perceived risk. Each Red Data Book usually deals with a specific group of animals or plants (e. reptiles, insects, mosses). They are now being published in many different countries and provide useful information on the threat status of the species. 

The IUCN Red List of Threatened Species (also known as the IUCN Red List or Red Data List), founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for the Conservation of Nature (IUCN) is the world's main authority on the conservation status of species.

Cell is a small unit which made the body of an organism which perform most of metabolic processes which are vital to organism like respiration, protein synthesis and secretion and excretion of materials. This is archived by differentiation and specialization of different cells. 

Example brain cells are differentiated to cardiac cells and other cells made human body which perform different functions which made human as she is.

A cell wall is defined as the non-living component, covering the outmost layer of a cell. Its composition varies according to the organism and is permeable in nature. The cell wall separates the interior contents of the cell from the exterior environment. It also provides shape, support, and protection to the cell and its organelles. However, this cellular component is present exclusively in eukaryotic plants, fungi, and few prokaryotic organisms.

The plant cell wall is composed of cellulose cellulose is a structural Carbohydrate and is because it is used in both protection and structure the plant cell wall consist of three layers each layer has its own unique structure and function.

If the object is moved towards the pin hole the size of the image increases. The size of image/ The size of object = Distance of screen from pin hole / Distance of object from pin hole.

Article 15 is based on the equality principle. It prohibits State from discriminating anyone based on grounds of religion, race, caste, sex or place of birth. Article 16 is also based on the equality principle of Article 14. It provides for equality of opportunity in matters of public or State employment and bars any discrimination to any citizen on grounds of religion, race, caste, sex, descent, place of birth, or residence. Under Article 17 “Untouchability'' is abolished and its practice in any form is forbidden. This article can be enforced against both the State as well as private individuals and the offence is punishable in accordance with special laws like the Protection of Civil Rights Act, 1955 and the Scheduled Caste and Scheduled Tribe (Prevention of Atrocities) Act, 1989.

The principle of equality means that one uniform law cannot be applied to all equally as some may not be similarly placed as others. So 'equality' treats equals similarly and unequals differently.

(a)  equality- to check child marriages

(b)  against equality principle.

 No, Intellectual Property Rights.

When we download someone else’s work or ideas and pass them as our own, then this practice is known as plagiarism.