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Priyanshu answered 1 year(s) , 10 month(s) ago

what is the derivation of mirror formula of concave and convex mirror?

Consider the shown figure where O is a point object and I is corresponding image.
CB is normal to the mirror at B.
By laws of reflection,

For small aperture...

Nov 16

• 29 Likes
• 115773 Views

Nov 16

An electric bulb is rated 220V and 100W. when it is operated on 110V, what will be the power consumed?

P = V 2/R
If V = 220 V we have

100 W = 220 2/R
R = 220 2/100 Ω = 484 Ω. This is the resistance of the bulb.

When V = 110 V,...

Jun 24

• 6 Likes
• 113237 Views

Jun 24

Anand answered 1 year(s) , 4 month(s) ago

What is the difference between a virtual image and a real image?

The following are the main differences between a real image and virtual image.

1.A real image can be caught on a screen whereas a virtual image cannot be caught on a screen.
2. A real i...

Dec 3

• 23 Likes
• 90866 Views

Dec 3

Priyanshu answered 1 year(s) , 6 month(s) ago

what is the uses of convex lens in daily life

Uses of convex lens are:
1) Convex lens is used in microscopes and magnifying glasses to subject all the light to a specific point.
2) Convex lens is used as a camera lens in cameras as they foc...

Jan 19

• 10 Likes
• 76053 Views

Jan 19

Syeda answered 1 year(s) , 11 month(s) ago

What is the difference between resistance and resistivity of a conducter? Please Explain?

May 7

• 4 Likes
• 67444 Views

May 7

Priyanshu answered 1 year(s) , 11 month(s) ago

I want all the formulas used in chapter electricity

The formulas used in class X are-
1- I,current=Q,charge/T,time
2- V,potential differnce=W,work done/Q,charge
3-V,potential difference=I,current*R,resistance
4-Resisitivity=(R,res...

Jul 9

• 4 Likes
• 60644 Views

Jul 9

The absolute refractive indices of glass and water are 4/3 & 3/2, respectively. If speed of light in glass is 2x108 m/s , calculate the speed of light in vacum and water.( 2015 Boards Que. )

Actually, n g = 3/2 and n w = 4/3.

Absolute Refractive Index of a medium = Speed of light in vacuum/Speed of light in the medium

Speed of light in glass =...

Mar 3

• 4 Likes
• 51020 Views

Mar 3

Amarnathreddy answered 4 year(s) , 10 month(s) ago

Calculate the number of electron constituting 1 coulomb of charge

Answer: The charge on an electron is negative and it is -1.6⨯10 -19 coulomb therefore, 1 C charge is carried by 1/ (-1.6⨯10 -19) = 6.25 ⨯ 10 18 electrons. He...

Jul 22

• 4 Likes
• 49459 Views

Jul 22

What is resistivity?

The resistivity of a material is the resistance of a wire of that material of unit length and unit cross-sectional area. The unit for resistivity is the ohm-metre.

The resistivi

...

Mar 22

• 3 Likes
• 47663 Views

Mar 22

Syeda answered 1 year(s) , 11 month(s) ago

State Joules law of heating. Mention SI unit Heat energy.

SI Unit of Heat Energy is Joule(J)

Apr 22

• 5 Likes
• 43654 Views

Apr 22

Syeda answered 1 year(s) , 11 month(s) ago

If the speed of light in vacuum is 3x10⁸ m/s, find the speed of light in a medium of absolute refractive index 1.5.

Refractive index of a medium = Speed of light in vacuum/Speed of light in a medium

1.5 = 3 x 10 8 / Speed of light in medium

Speed of light in the medium = 3 x 10...

Jan 28

• 3 Likes
• 42666 Views

Jan 28

what are the factors on which the resistance of a conductor depends? what happens to the resistivity of a conductor when its length is doubled?

Resistance of a conductor directly depends upon Length of the wire L
Inversely depends upon Area of Cross section of the conductor 1/A
Nature of material used.
Therefore, R

...

Jul 20

• 4 Likes
• 40807 Views

Jul 20

Janhavi answered 4 year(s) , 3 month(s) ago

If the image formed by a mirror for all positions of the object placed in front of it is always erect and diminished, what type of mirror is it ? Draw a ray diagram to justify your answer. Where and why do we generally use this type of mirror?

A convex mirror forms an erect diminished virtual image for all the positions of the object placed in front of it.

A convex mirror is used as rear view mirrors in automobiles...

Mar 3

• 3 Likes
• 37358 Views

Mar 3

8. What is the resistance of an ideal voltmeter and ammeter ? how are they connected in a circuit?

The internal resistance of an ideal voltmeter is infinity and the internal resistance of an ideal ammeter is zero.
Ammeter is connected in series and voltmeter is connec...

Jun 6

• 2 Likes
• 34165 Views

Jun 6

Amarnathreddy answered 4 year(s) , 2 month(s) ago

Prove F = ma

Derivation of Newton’s Second Law of Motion

Newton’s second law of motion states that the rate of change of momentum of an object is Proportional to the applied unbalanced force...

Mar 17

• 5 Likes
• 32994 Views

Mar 17

why does the ray passing through the centre of curvature of a concave mirror retraces it's path.

A ray of light passing through the centre of curvature of a concave mirror retraces its path (gets reflected along the same path), because as the ray of light passes throu

...

Nov 21

• 0 Like
• 32741 Views

Nov 21

Agam answered 1 year(s) , 2 month(s) ago

An object 5 cm in size is placed at a distance of 20 cm from the concave mirror of focal length 15 cm. At what distance from the mirror should..

Object-size, h = + 5.0 cm;
Object-distance, u = – 20.0 cm;
Focal length, f = –15.0 cm;
Image-distance, v = ?
Image-size, h′ = ?
Mirror formula is             (1/v) + (1/u...

Dec 5

• 2 Likes
• 32077 Views

Dec 5

What is meant by power of a lens ? Name and define its S.I. unit.

The ability of a lens to converge/diverge a beam of light rays is expressed in terms of its Power( P).
P=1/f
The SI unit of power of lens is Dioptre.It is den...

Mar 8

• 3 Likes
• 31275 Views

Mar 8

Sharathchandar answered 3 year(s) , 10 month(s) ago

Why an ammeter is connected in series while a voltmeter is in parallel?

(i) The internal resistance of the ammeter is very low.If we connect it in series, then
the maximum current can flow through it. So the accurate current should be
measured. I...

Jul 11

• 1 Like
• 31071 Views

Jul 11

Agam answered 1 year(s) , 9 month(s) ago

twinkling of stars

The phenomenon that causes stars to twinkle is atmospheric refraction. That is, the air above us is a big ocean of not very dense fluid that has a small bending effect on light that passes through it. If it wer...

Feb 24

• 4 Likes
• 29855 Views

Feb 24

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