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option B burning of fossil fuels release oxides of carbon , nitrogen and sulphur in the atmosphere.

option b is correct..

lamba= 5×10^-5cm=5000 angstrom

In electromagnetism, displacement current is a quantity appearing in Maxwell's equations that is defined in terms of the rate of change ofelectricdisplacement field. Displacement current has the units ofelectriccurrent density, and it has an associated magneticfield just as actual currents do.

causes also

Displacement current are the current due to the changing of the electric field inside the plate of capacitor.so, when the electric field will change , at that tym the displacement current will produce .

In the starting the friction force is greatest. When we have pushed the box little, the friction force is slowing being overcome.

and so, the force we are applying on the object, is stronger than the friction force applied by the object... right?

Total distance travelled by train = 1445 km

Journey begins at 4:45 PM and train reaches its destination at 9:45 AM on the next day.

Time of travel on Day 1 = (12:00-4:45) = 7 h 15 min

Time of travel on Day 2 = 9 h 45 min

Total time taken = 7h 15 min + 9 h 45 min = 17 h

Speed = Distance/Time =1445/17 = Speed = 85 km/h Ans.

to convert speed in m/s we need to multiply by 18/5.

Speed in m/s = 85*18/5 = 306 m/s Ans.

D. Tissue paper

Explaination : Its capable of being decomposed by bacteria or other living organisms.

b number are right answer

velocity

V=√2GM/R =(2GM/R)^1/2 By putting the dimensional formulas of G,M,R,and V We get , V =(M^-1 L^3 T^-2)(M^1 L^0 T^0)(M^0 L^1 T^0)^1/2 =(M^0 L^2 T ^-2)^1/2 =(M^0 L^1 T^-1)=L.H.S And we know thatV=( M^0 L^1 T^-1) R.H.S So R.H.S =L.H.S

The name hydraulic means “operated by the pressure created by forcing water (or) another liquid”. Washing ore with water is known as hydraulic washing. Gold mines make use of the hydraulic washing technique.

An upward stream of running water is used to wash powdered ore. The lighter particles of the gangue are washed away and the heavier ore is left behind. This technique separates the gangue from the ore using the difference in their specific gravities. It is, also known as gravity separation.

When borax is dissolved in water it ionizes and hydrolysis of borate ion gives OH (the hydroxyl ion) and boric acid. Since boric acid is a weak acid AND Na-OH is strong a alkali an aqueous solution of borax is alkaline in nature.

3.5V is correct answer

option 2 is correct thanks

Option A is rightfirst we calculatedcurrentthen applied KVL

option a & b is incorrect

since F ∞ x

so, U ∞ x². ( u = f.ds)..

Ray optics (or geometrical optics), describes light traversal (propagation in terms of physics) in terms of "rays". The "ray" in geometric optics is an abstraction, or "instrument", which can be used to approximately model how light will travel. Light rays are defined to propagate in a straight path as they travel in a homogeneous medium (such as air, ).As light travels through space, it oscillates in amplitude (like any other wave). In this image, each maximum amplitude crest is marked with a plane to illustrate the wavefront. The ray is the arrow perpendicular to these surfaces.

There are two methods to solve this.

METHOD 1 : Using only Motion Equations.

m = 0.02 kgu = 300 m/sv = 0d = 0.03 m(Note everything is in SI system of units)

a = (v×v - u×u)/2s = (0-900)/0.06 = -15000 m/s^2- sign indicates that acceleration is opposite to motion. This type of acceleration is also called retardation or deceleration.

So, Force = ma = 0.02 × 15000 = 300 newton (Ans)

METHOD 2 : Using Conservation of Energy.

So, we have Work done = Change in Kinetic EnergyHence, Fd = mv×v/2F = mv×v/(2d) = 0.02 × 30 × 30 / 0.06 = 300 newton (Ans)

work done, fd=mvxv/2d==0.0××30×30/0.06=300 newton

300 Newton is the answer

so 1/3= alpha*2001/600= alphaalpha = 1.67*10^-3

Thank you sir but answer is wrong

1) Dimensions of greenhouse:

l = 30 cm, b = 25 cm, h = 25 cm

Total surface area of green house = 2(lb + bh + lh)

= 2(30×25 + 25×25 +25×30)

= 4250 cm2

(ii) Length of the tape needed = 4(l + b + h)

= 4(30 + 25 + 25)

= 320 cm

Only the rays in geometrical optics can cross.

The lines of forces in electrostatics represent the electric field and if they cross it would mean that there are two values of electric field at a point which is not possible.

In magnetism, the lines represent the direction of magnetic force as well as tangent to streamlines in fluid represent the direction of flow. Hence, they cannot intersect.

(a) is correct option

pressure at depth = DENSITY*g*H

=> 8968960 = 1040*9.8*H=> H = 8968960/(1049*9.8)=> H = 880m

Here we shall first use the continuity equation

av = a'v'

where

a and a' are cross-sectional areas at points 1 and 2 respectively and

v and v' are the velocities of fluid at points 1 and 2 respectively

so,

a =0.02 m^2

v =2 m/s

a' =0.01 m^2

now, as

v' = av / a'

so,

v' = 0.02x2 / 0.01

thus,

v' = 4 m/s

..

now, the Bernoulli's equation is given as (here z = z' - 0)

P/ρ + (1/2)v^2= P'/ρ + (1/2)v'^2

or

P/ρ + (1/2)v^2- (1/2)v'^2= P'/ρ

or

P' = P + (ρ/2)[v^2- v'^2]

now, P = 4 x 10^4N/mm^2= 4 x 10^10N/m^2

and ρ = 1000 kg/m^3

so,

P' = 4 x 10^10+ (1000/2)[2^2- 4^2] ~ 4 x 10^10N/m^2

the answer is close to the initial value

Optical aids for low vision can range from reading glasses, magnifiers to small telescopes depending on the severity of visual impairment. Such devices differ from the reading glasses or the magnifying glasses that we are familiar with. Low vision devices are never all purpose devices and are built with a very specific use in mind. We should think of the low vision optical aids as specific where one device may be used for reading a mail, another for watching movies, and yet another for seeing menus at a restaurant.Braille is a system that uses combinations of raised dots to spell letters and numbers. It’s used by people who are blind or partially sighted to help them read and write.Louis Braille developed this system

1. They are inexhaustible and renewable.

2. They are obtained at low cost and can be used to meet the ever growing demands of population.

3. If we use non conventional energy sources we can save resources for our future generation. We should move towards sustainable development.

4. As we know conventional sources of energy can't be renew that's why we should not use it in large amount.

Electric flux = E*S

= (3i+5j+6k).(10j)

= 5.10

= 50 units

Non conventional sources of energy include solar, wind, tidal, geothermal. bio gas etc. They are relevant because :

a. They are inexhaustible and renewable.

b. They are obtained at low cost and can be used to meet the growing needs of population and industrialization.

c. India is blessed with abundance of sunlight, bio mass, wind, water which can serve as alternative to conventional sources of energy.

d. Use of non conventional sources of energy is in tune with objective of sustainable development as it does not cause environmental hazards.

e. Non conventional sources of energy can certainly ensure security of energy supply to meet our future needs.

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A conservative force is a force with the property that the total work done in moving a particle between two points is independent of the taken path. ... If a force is conservative, it is possible to assign a numerical value for the potential at any point.Theconservation of mechanical energy. ... The principle of theconservation of mechanical energy statesthat the totalmechanical energyin a system (i.e., the sum of the potential plus kinetic energies) remains constant as long as the only forcesacting areconservative forces

It is called theprincipleoflinear momentum, or balance oflinear momentum. If there are no forces applied to a system, the totalmomentumof the system remains constant; the law in this case is known as the law ofconservation of (linear)momentum.

Α = angular acceleration = rad/sec²t = time = 5 secω₀ = initial angular velocity = 0 rad/sec as the body is at rest at t = 0 sec.θ = total angle rotated from t=0 to t, = 50 * 2π radiansTotal angle rotated = θ = ω₀ t + 1/2 * α * t² (It`s like: total distance = s = u t + 1/2 * a * t²)So 100 π = 0 * 5 + 1/2 * α * 5² α = 8π rad/sec² = 8π /(2π) revolutions/sec² , as 1 revolution = 2π rad. = 4 revolutions/sec². α = 4 rev/secTotal angle rotated = θ = ω₀ t + 1/2 * α * t² 50 rev = 0 * 5 + 1/2 * α * 5² α = 4 rev/sec²

Here, mass of cylinder (m) = 10 Kg Radius (r) = 15 cm = 0.15 m Inclination of plane (∅) = 30° coefficient of friction (u) = 0.25

(a) friction = mgsin∅/(1 + mr²/I) For solid cylinder (I) = mr²/2 Fr = mgsin∅/3 = 10 × 9.8 × 1/2 × 1/3 = 16.3 N

(b) force of friction acts perpendicular to the direction of the displacement.So , work done against during rolling .W = Fscos90° = 0

(c) for rolling without slipping use formula, u = tan∅/( 1 + mr²/I)For solid cylinder u = tan∅/3 tan∅ = 3u = 3×0.25 = 0.75 = tan36°54'∅ = 36°54' ≈ 37°

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Ans :- linear velocity refers to an object's speed as it moves along a straight line.

Angular velocity is the rate of velocity at which an object or a particle is rotating around a center or a specific point in a given time period. It is also known as rotational velocity. Angular velocity is measured in angle per unit time or radians per second (rad/s).

The angular acceleration is also known as rotational acceleration. It is a quantitative expression of the change in angular velocity per unit time.The acceleration vector, magnitude or the length is directly proportional to the rate of change in angular velocity.

Angular velocity can be considered to be a vector quantity, with direction along the axis of rotation in theright-hand rulesense.

For an object rotating about an axis, every point on the object has the same angular velocity. The tangential velocity of any point is proportional to its distance from the axis of rotation. Angular velocity has the units rad/s.

Derivation :

You're moving in a circle of radius r, so the distance you travel in one full trip round the circle is 2.pi.r and you're doing it in one time period, T

speed, v = distance/time = 2.pi.r/T

w = angular speed, and you complete 2 pi radians in time T, so w = 2pi/T

so v=rw

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