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Ask questions which are clear, concise and easy to understand.

kinematics
Posted by Aryan Singh (Aug 20, 2017 6:25 p.m.) (Question ID: 14582)

what is accelration
Posted by Aryan Singh (Aug 20, 2017 6:25 p.m.) (Question ID: 14581)

fifrunn
Posted by Aryan Singh (Aug 20, 2017 6:24 p.m.) (Question ID: 14580)

Sin 1degree in fraction
Posted by Aditya Dubey (Aug 20, 2017 5:48 p.m.) (Question ID: 14543)

1/2-1/3
Posted by Zahiruddin Babar Khan (Aug 18, 2017 7:47 p.m.) (Question ID: 12979)

Where can i find study material for jee mains
Posted by Chirag Sharma (Aug 17, 2017 10:05 p.m.) (Question ID: 12534)

Why lithium is strongest reducing.agent and caesium is not
Posted by Manju Malik (Aug 14, 2017 4:25 p.m.) (Question ID: 10474)

Give The deffinition of cross product
Posted by Vineet Kumar (Aug 13, 2017 6:24 p.m.) (Question ID: 10008)

why value of trigonometric sine is positive in second quadrant
Posted by Anurag Kumar (Aug 12, 2017 10:16 p.m.) (Question ID: 9479)

• Because sine is p/h and if you will prepare a right triangle in second quadrant then only base will be in negative x otherwise both perpendicular and hypotenuse will be positive so sine and cosec are positive in second quadrant..

Posted by Neeraj Kumar Sharma (Aug 19, 2017 1 a.m.)
• Because only sine and cosine will positive on 2nd quadrant
Answered by Khan Israil (Aug 17, 2017 12:06 p.m.)
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• Because all are positive in 2nd quadrant
Answered by Anshul Gupta (Aug 16, 2017 5:27 p.m.)
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why trigonometric ratio are not change at an angle 180 and 360 but they change at 90 and 270
Posted by Anurag Kumar (Aug 12, 2017 10:13 p.m.) (Question ID: 9476)

• Because at odd no of 90 x axis is changed by y axis and vice versa but at even no the axis is not changed just +Ive axis changed to negative and vice versa

Posted by Neeraj Kumar Sharma (Aug 19, 2017 1:01 a.m.)
why molecularity of a reaction can not be more than 3
Posted by Anurag Kumar (Aug 12, 2017 10:05 p.m.) (Question ID: 9471)

What is primitive
Posted by Prateek Agarwal (Aug 11, 2017 7:20 p.m.) (Question ID: 8754)

• It is the integration..
Posted by Prateek Agarwal (Aug 11, 2017 7:21 p.m.)
What is physic
Posted by Upajit Gayary (Aug 11, 2017 4:43 p.m.) (Question ID: 8664)

• Physics is the branch of science which deals with the study of environment and natural phenomenon.
Answered by Rinku Sharma (Aug 12, 2017 8:21 a.m.)
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• Physics is the natural science that involves the study of matter and its motion and behavior through space and time, along with related concepts such as energy and force.

Answered by Ashutosh Kumar (Aug 11, 2017 5:37 p.m.)
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Young's modulus steel and coper are equal are not
Posted by Kashi N (Aug 10, 2017 11:01 p.m.) (Question ID: 8464)

The moon is observed from the two diametrically opposite points A and B on Earth.The angle theta subtended at the moon by the two directions of observation is 1°54'.Given the diameter of Earth to be about 1.276×10^7m.compute the distance of the moon from the Earth.
Posted by Ratnadip Patil (Aug 10, 2017 10:53 a.m.) (Question ID: 8015)

(X-y) dy/DX=x+2 is homogeneous
Posted by Aditya Roy (Aug 09, 2017 12:01 p.m.) (Question ID: 7499)

Define democracy discuss briefly it's kinds
Posted by Alsem Tirkey Ritesh (Aug 09, 2017 7:22 a.m.) (Question ID: 7450)

what is urine

Posted by Abhishek Chhabra (Jul 30, 2017 1:10 p.m.) (Question ID: 7015)

• Urine is a liquid by-product of metabolism in the bodies of many animals, including humans. It is expelled from the kidneys and flows through the ureters to the urinary bladder, from which it is soon excreted from the body through the urethra during urination.

Answered by Sahdev Sharma (Jul 30, 2017 11:09 p.m.)
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The rotation of the earth having radius R about its axis speeds up to a value such that a man at latitude angle 600 feels weightless. The duration of the day in such case will be?

Posted by Bhavesh Rajoria (Jul 23, 2017 7:22 a.m.) (Question ID: 6858)

A spherical black body with a radius of 12cm radiates 440w power at 500K.If the radius were halved and the temperature doubled, the power radiated in watt would be

Posted by Ashok Kumar S (Jul 22, 2017 7:41 a.m.) (Question ID: 6825)

• Let original radius = r

Original temperature = T

Original power radiated = P

According to Stefan-Boltzmann Law, Power radiated by black body = {tex}P = σAT^4=\sigma 4\pi r^2T^4{/tex}

{tex}=> 500 = 4\sigma \pi r^2T^4{/tex}

New radius = {tex}r\over 2{/tex}

New temperature = 2T

New power P` = {tex}4\sigma \pi \times {r^2\over 4}\times 16T^4{/tex}

{tex}4\times (4\sigma \pi r^2T^4)= 4\times P{/tex}{tex}= 4\times 450= 1800{/tex}

Power becomes 1800 W

Answered by Sahdev Sharma (Jul 22, 2017 12:05 p.m.)
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more stable metal gold silver platinum

Posted by Shubham Baghel (Jul 17, 2017 1:29 p.m.) (Question ID: 6708)

A sample of 1.0g of solid Fe2Oof 80%purity is dissolved in a moderately concentrated HCl solution which is reduced by zinc dust. The resulting solution required 16.7 mL of a 0.1M solution  of the oxidant. Calculate the number of electrons taken up by the oxidant.

Posted by Bharti Earekar (Jul 17, 2017 11:53 a.m.) (Question ID: 6706)

What is the vector form of ohms law?

Posted by Pratik Banerjee (Jul 15, 2017 1:21 p.m.) (Question ID: 6650)

• Current density,J=σE

where,σ-conductivity(scalar quantity) reciprocal of resistivity( ρ=R A/L)

E-Electric field (vector quantity),E=Volt/Length

​​​​​​S.I unit of J (vector quantity)is Am-2.

Dimesionally ,

[J]=[σ][E]

or, A/m2=(m/Ωm2) (V/m)

Or,A= V/Ω

 V=A*ohm(Ω )

So, J=sigm * electric field

Which vector form of ohm 's law:

V=I R

Posted by Deepak Sah (Jul 18, 2017 1:43 a.m.)

(sinA+cosA)÷(sinA-cosA)=x÷y, prove that xsquare +ysquare=2

Posted by Tausiful Haque (Jul 11, 2017 2:56 p.m.) (Question ID: 6561)

• The proof is possible when sinA+cosA=x and sinA-cosA=y.

If division is there then proof is x²+y²=k²/2

Posted by Soumya Ghoshal (Jul 31, 2017 10:26 p.m.)
• Sin…1\2√sin
Answered by Sachin Ray (Aug 11, 2017 7:22 p.m.)
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• x²+y²=(sinA+cosA) ² +(sinA-cosA) ²

= 2

OR,

x+y=k sinA, x-y=k cosA

x²+y²=1/2(k²sin²A + k²cos²A)

= 1/2 (k²(sin²A + cos²A))

= 1/2 *k²

= k²/2

Answered by Soumya Ghoshal (Jul 31, 2017 11:27 p.m.)
Thanks (1)

What is steady current?

Posted by Pratik Banerjee (Jul 11, 2017 10:31 a.m.) (Question ID: 6559)

• When the magnitude of the current does not vary with respect to time.
Answered by Priyanka Mishra (Aug 15, 2017 9:34 a.m.)
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• A constant current is a type of Direct Current (DC) that does not change its intensity with time.

Answered by Dr Pathikrt Banerjee (Jul 11, 2017 11:24 a.m.)
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Draw square root of 11on number line

Posted by Preeti Mandle (Jul 06, 2017 5:47 p.m.) (Question ID: 6427)

• Answered by Soumya Ghoshal (Jul 31, 2017 9:54 p.m.)
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a projectile is projected from angle of prism at an angle alpha and it crosses the prism and reach exactly edge of the bottom.if alpha and beta are angle of prism then show that tan teta is equal to tan alpha plus tan beta

Posted by Vishwa Vishwa (Jun 28, 2017 6:30 a.m.) (Question ID: 6224)

If f-1 exist if f is

A) one to one function

B) surjective

C) bijective

D) into

Posted by Saurabh Tharu (Jun 25, 2017 9:43 p.m.) (Question ID: 6180)

• The answer is option A and B

Answered by Soumya Rai (Jun 25, 2017 10:24 p.m.)
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1. The maximum value of 10x-5x2-1 is

Posted by Konda Thirumala Rao (Jun 25, 2017 6:48 a.m.) (Question ID: 6162)

• = -5 ( x- 2x) - 1

= -5 (x- 2x + 1 - 1) - 1

= -5 (x - 1)2 + 5 - 1

= 4 - 5 (x - 1)2

Since ( x - 1 )2 >= 0

-5 (x - 1)2 <= 0

4 - 5 (x - 1)2 <= 4

Answered by Bipin Dubey (Jul 19, 2017 6:45 p.m.)
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• 4

Answered by Payal Singh (Jun 25, 2017 9:48 p.m.)
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Hello . My doubt is that I want solution ( How to solve it , step-by-step)  of the following Question :  " if (Alpha)+(Beta)=3 and (Alpha)(Cube)+(Beta)(Cube)=7 , then (Alpha) and (Beta) are roots of equation "........................ .I hope that you  would reply me soon .

Posted by Abhinav Ambatipudi (Jun 14, 2017 6:44 p.m.) (Question ID: 5905)

• a+b=3  i. e. b=3-a

a ³+b³=7 (Given)

(a+b) ³-3ab(a+b)=7

Or, 27-9ab=7

Or, ab=20/9

Now, a(3-a)=20/9

Or, 9a²-27a+20=0

Solving by Sreedhar Achrya's formula,

We get,

a=5/3 or 4/3

and b=4/3 or 5/3

Answered by Soumya Ghoshal (Jul 31, 2017 10:21 p.m.)
Thanks (0)