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In electronics, acommon collectoramplifier (also known as anemitter follower) is one of three basic single-stage bipolar junction transistor (BJT) amplifier topologies, typically used as a voltage buffer.option c

We know Area of a rectangle islength *breadthArea = 725/16cm^2one side is 25/4 cmside x 25/4 = 725/16side x 6.25 = 45.3125now side will beside = 7.25 cm

Laws of refractionstate that: The incident ray, reflected ray and the normal, to the interface of any two given mediums; all lie in the same plane. The ratio of the sine of the angle of incidence and sine of the angle ofrefractionis constant.

option b because band c reflects in figure of b and c

a light beam after striking a plane and smooth surface moves back in the same medium

When light falls on a smooth and shiny surface, it bounces off. This phenomenon is called reflection.

Vibration, is a mechanical phenomena which results in periodic back-and-forth motion of the particles of an elastic body or medium, commonly resulting when almost any physical system is displaced from its equilibrium condition and allowed to respond to the forces that tend to restore equilibrium.

tq bro

Given,

u=30 cm

f=20 cm

v=?

Here,

1/u + 1/v = 1/f

1/30 + 1/v = 1/20

1/v = 1/20 - 1/30

1/v = 1/60

v= 60 cm

( u, v, f are always in ‘+’ in concave.

But ‘-’ in convex)

Now,

(Since image is formed on the same side of the object , the image is real)

v-u = 60 - 30 = 30 cm

So the distance between object and image is 30 cm.

For concave mirror

u= -20 cm

f= -30 cm

By using mirror formula,

1/v + 1/u = 1/f

1/v + 1/-20 = 1/-30

v= 60 cm

Positive sign indicates that image is in opposite side of mirror

Therefore,

The distance between image and object = 60+20 = 80 cm

λ= v/f

where

λ

is the wavelength

f

is the frequency and

v

is the speed

v = 299792458 m/s

because it is electromagnetic wave

f = 10^7 Hz

hence wavelength =30m

🌎 PLEASE MARK MY ANSWER AS BEST AND GIVE ME SOME LIKES 🌎✌️The answer will be : option a) the total kinetic energy is conserved

The linear momentum is conserved in inelastic collision. Kinectic energy is not conserved.

(d) is correct option

Magnification = 1/3

1/3 = -v/u u/3 = v

mirror formula

1/f = 1/v + 1/u sub v in formula

1/-20 = 3/u + 1/u 1/-20 = 4/u 1/u = 1/-80 u=-80

Object's size (h1) = 2 cmFocal length of convex lens (f) = 10 cmObject distance from the lens (u) = -15 cm Image distance ( v) = ?Image size (h2) = ?

We know,

1/v - 1/u= 1/f

1/v = 1/f + 1/u

1/v = 1/10 - 1/15

1/v = 1/30

Thus, v = 30 cm

Now, v = 30 cm, 'v' is positive, that means the image is formed on the right side of the lens. That's why it is REAL and INVERTED.

Now, magnification =?

Linear magnification (m) = Size of image / Size of object = h2 / h1 = v/u

m = h2/2 = 30/-15

m= h2 × -15 = 30×2

m = -15 h2 = 60

h2 = 60 / -15

h2 = -4 cm

Size of the image = -4 cmIt's in negative , that means that the image is INVERTED.

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Magnification = 1/31/3 = -v/u-u/3 = v

Here,u = Object distance v = Image distance

Mirror formula1/f = 1/v + 1/u

Substitute v in formula1/20 = - 3/u + 1/u1/20 = -2/u 1/u = 1/-40 u = - 40

Therefore object distance from optical center is 40 cm

i thik its b but try to solve

Thaks

1) The image formed is virtual.2) The image formed is erect.3) The image formed is smaller in size than the object.4) The image is formed in front of the mirror.

The object is placed at a distance of30cm from a concave lens of focal length15cm.

Characteristics of the image:

The lens is concave and hence the image would be virtual.

The image is virtual and hence it would be erect.

The distance of the object from the mirror is twice the focal length and hence the image would be at the same position as the object.

Since the distances of the object and image from the lens are equal to each other, the magnification is 1 i.e. the size of the image is the same as that of the object.

Thanks

CONCAVE MIRRORS;1. They always produce real and inverted images except when an object is placed between the mirror pole and the focus which gives erect virtual images. (for real objects)2. They produce magnified, diminished and same size images. 3.A parallel beam of incident light is concentrated on its focus and thus such a mirror is called a convergent mirror. Also a light source placed at the focus produces a parallel light beam.4.Sign convention: The focal length and radius of curvature are taken as negative.If focal length is at 20cm then radius of curvature is 2f=40cmhencethe image is at centre of curvaturehence the image formed will be real inverted at centre of curvature and of the same size

U=-60cm f= -30cm 1/f=1/v-1/u1/v=1/f+1/uon substituting v=-10cmm=v/um=-10/-30m=1/3=.33so the magnification is positive so it is a virtual erect image .m isless than 1 so the image is diminished .and v is negative so the image is formed on the same side of the lens.

sgtwbst

dgyftsveceehyveveys

Distance travelled = 2* distance between the surface and the source.Speed = distance/time=> 342*3=2*d=> d = 513 m.

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The velocity of sound in dry air isapproximately 343 m/s at a temperature of 25 °C. Therefore, the reflecting object must be more than17.2mfrom the sound source for echo to be perceived by a person located at the source.

In the initial setup, the object distance is 40 cm, which gives 24 cm image distance given the focal length of 15 cm. (equation: 1/15= 1/40 + 1/i)

The second equation changes object distance to 20 cm (40–20), which results in 60 cm as the image distance. (equation: 1/15= 1/20 + 1/i)

The difference between 60 and 24 is 36 cm (in the direction away from mirror).

White light consists of waves of inumerable wavelengths starting from violet to red colour. Therefore if monochromatic light in Young’s interference experiment is replaced by white light, then the waves of each wavelength form their separate interference patterns. The resultant effect of all these patterns is obtained on the screen.

The path difference between waves starting from S1 and S2

at the location (M) of central fringe is zero,i.e., for pointMof screenS1m− S2m=0

i.e., the waves of all colours reach at mid pointMin same phase. Therefore the central fringe (atM) iswhite. As fringe width ,i.e., wavelength increases in order of colours denoted by VIBGYOR therefore on either side of it some coloured fringes are obtained in order of colour VIBGYOR. That is the violet (V) fringe appears first and the red (R) the last. After this the fringes of many colours overlap at each point of the screen and so the screen appears uniformly illuminated.

Thus if we use white light in place of monochromatic light the central fringe is white, containing on either side a few coloured fringes (in order VIBGYOR) and the remaining screen appears uniformly illuminated.

DefinitionOfDispersionOfLight. The process of splitting ofwhite lightinto seven colours is calleddispersionoflight. ... Example: Through a window glasslightreflects as well as refracts.Wecan observe the objects through the glass due to refraction (lightpasses through the glass

Q= m c∆tc= 4.816now= 100*4.816*9043344 43kcal

43 kcal right answer bhai

a correct answer is 9

(P + a/V2) (V - b) = RTP is pressure, V is volume and T is temperature.[P] = [F/A] = [MLT−2/L2] = [ML−1T−2][V] = [L3]We cannot add or subtract quantities of different dimensions. Therefore[P] = [a/V2] ⇒ [a] = [PV2] = [ML−1T−2L6] = [M L5T−2]∴ [a] = [M L5T−2]Similarly,[b] = [V] = [L3]

When light waves are reflected, they undergo a phase change of 180

4) 180 is the right answer