Explore topic-wise InterviewSolutions in .

Convex mirrorsare commonly used asrear-view(wing)mirrors in vehiclesbecause they give an erect, virtual, full size diminished image of distant objects with a wider field ofview. Thus,convex mirrorsenable the driver toviewmuch larger area thanwouldbe possible with a planemirror.

Hey DEEPAK, if you really like the answer, Mark it as best bro..

because it produces virtual image. ...

Because the image is smaller, more image can fit onto themirror, so a convexmirrorprovides for a larger field ofviewthan a planemirror. This is why they are useful. They areusedwhenever amirrorwith a large field ofviewis needed. For example, the passenger-siderearview mirroron acaris convex.

a) Concave Mirrorb) Convex Mirrorc) Concave Mirror

thank-you so much

thank you so much

sin 90∅ angle is best.

We have,m= 100kgg= 10 m/s²t = 10swork done = mghW = 100 X 10 X 20Work done = 20000 JP = Work done/time takenPower = 20000/10Therefore, power = 2000 W

thankyou

Velocity = 90 km/hr = 25 m/s.

Power = 25 kW = 25,000 W.

Work = Kinetic energy

∴ W =1/2 mv²

⇒ W = 375000

Since, Power = Work/time.

⇒ Time = Work/Power

⇒ Time = 375000/25000

∴ t = 15 s.

Given,Speed = 54 km/hr

To convert 54 km/hr in m/s

Convert km into m Multiply by 1000 and convert hour into sec multiply by 3600

Therefore,54 km/hr = 54 * 1000/3600= 54 * 5/18= 3*5 = 15 m/s

54 kilometres per hour=

15 metres per second

since (54km/hr )/3.6=15 m/s

P:E = mgh = 10x10 =100as force=mg

P:E = mgh = 10x10 =100Jas force=mg

A is the correct answer to that question

option c is right 00 to FF

good

Consider a completely demagnetized ferromagnetic material. [Completely Demagnetised material is the one in which B=H =0].It will be subjected to increasing values of magnetic field strength H and the corresponding flux density B measured.

The result is shown in the below figure by the curve o-a-b.At the point b, if the field intensity (H) is increased further the flux density(B) will not increase any more.This is calledsaturation( the material is said to be saturated). In this figure b-y is called assaturation flux density.

Now if the field intensity (H) is decreased, the flux density (B) will follow the curve b-c.When field intensity (H) is reduced to zero, flux remains in the iron.This is called asremanent flux density or remanence.It is shown in the figure as o-c.

Now if the H is increased in the opposite direction, theflux density decreases as will.

It will decrease until the point d. Here the flux density (B)is zero.

The magnetic field strength (points between 0 and d) required to remove the residual magnetism, i.e. reduce B to zero. It is called thecoercive force.

Now if the H is increased further in the reverse direction causes the flux density to increase in the reverse direction till the saturation point ( here point-e).

If H is varied backwards from 0x to 0y, the flux density(B) follows the curve e-f-g-b, similar to curve b-c-d-e.

From the figure the clear thatthe flux density changes lag behind the changes in the magnetic field strength.

This effect is calledHysteresis.

The closed figure b-c-d-e-f-g-b is called theHysteresis Loop (or the B/H Loop).

The question can be done by options only..as when 1 disc is cut from +y side... the com will shift to -y (heavy mass)

and when again 1 disc is cut from +x, the com will shift to -x (heavy mass)

so, all together.. the CoM will shift to (-x,-y)

so, option 3 is matching..here only.

Therefractive indexof the medium is inversely proportional to thevelocity of lightin it. As therefractive indexof a medium increases, thespeed of lightgoing through that medium decreases. Where is thevelocity of lightthrough that medium and is therefractive indexof the medium thelightis passing through.

pole strength = magnetic moment /length here magnetic moment = 1.5A/m² and length = 15cm = 0.15m or pole strength = 1.5/0.15 = 10A/m

The refractive index of amedium depends on the wavelength of the light. If the wavelength of light isless the refractive index will be high. Secondly it depends on the density ofthe substance. The intermolecular force between the molecules of the substancewill affect the refractive index. The index is also influenced by thepermeability of the material.

optical density, wavelength of the lighttemperature

Centre of mass of upper rod is at O.Centre of mass of lower rod is at L/2 from O.

Along vertical liney_cm = (m1y1 + m2y2) / (m1 + m2)= (0 + mL/2) / (2m)= L/4

∴ Centre of mass of system is at lower rod and below L/4 from point O

Centre of mass of upper rod is at O.Centre of mass of lower rod is at L/2 from O.

Along vertical liney_cm = (m1y1 + m2y2) / (m1 + m2)= (0 + mL/2) / (2m)= L/4

∴ Centre of mass of system is at lower rod and below L/4 from point O

how centre of mass of upper loas is 0 ?

Refractive Index = Speed of light in vaccum/speed of light in medium

1.5 = 3×10^8/speed of light in glass

Speed of light in glass= (3×10^8)/1.5= 2× 10^8 m/s

In the context of Physics, a polar vector may refer to i) a vector represented using the spherical/polar coordinate system (its length and the angle it makes with a fixed axis (refer to figure)), or ii) a vector whose sign reverses on inversion of signs of the coordinate system. Some examples are velocity, force and linear momentum.

Refractive indexis equal to thevelocityof light c of a given wavelength in empty space divided by itsvelocityv in a substance, or n = c/v.