CBSE > Class 12 > Physics | CBSE Board | Homework Help

See at page no. 260,261 in NCERT part 1 (alternating current)....kafi ache se explain kiya hua h.....agar NCERT M samaj ni aaye to SL Arora M se to 100% aa jaayega....

1Thank You

G K 7 years, 2 months ago

Efficiency=P(output)/P(input)×100.....

2Thank You

Satyam Kumar 7 years, 2 months ago

Please give me mathematical formula to find ing the efficiency of transformer

0Thank You

G K 7 years, 2 months ago

. Transformers are the most highly efficient electrical devices......nearly about 95-97%

1Thank You

ANSWER

What is maximum power transfer theory?

Posted by Satyam Kumar 7 years, 2 months ago

CBSE > Class 12 > Physics

2 answers

G K 7 years, 2 months ago

The efficiency while giving maximum power is only 50% as 50% power is lost across internal resistance.

1Thank You

G K 7 years, 2 months ago

It states that, ....to obtain maximum external power from a source with a finite internal resistance, the resistance of the load must equal the resistance of the source as viewed from its output terminals....

2Thank You

ANSWER

Wht is main difference b/w Farady's Law nd Self inductance......??

Posted by Shubham Tiwari 7 years, 2 months ago

CBSE > Class 12 > Physics

1 answers

Satyam Kumar 7 years, 2 months ago

In faraday's law when coil is placed in varrying magnetic field by this e.m.f is induced across the coil.this due to phenomenon of electromagnetic induction. In Self induction the value of current is changes across the coil by this e.m.f is induced in the coil.

1Thank You

ANSWER

Tomorrow please my physics paper Can anybody help

Posted by Akshat Sharma 7 years, 2 months ago

CBSE > Class 12 > Physics

4 answers

Hy Shona 7 years, 2 months ago

U are right satyam.I also think so

0Thank You

G K 7 years, 2 months ago

0Thank You

Satyam Kumar 7 years, 2 months ago

Megha you're very intelligent

1Thank You

G K 7 years, 2 months ago

I only give my best wishes.....ALL THE BEST?????......

0Thank You

ANSWER

What do you mean by impedence

Posted by Shivam Sagar 7 years, 2 months ago

CBSE > Class 12 > Physics

1 answers

Akshat Sharma 7 years, 2 months ago

Impedence denoted by Z Z = √R^2+(XL-XC)^2 R = Resistance XL= Inductive reactance XC= Capacitive reactance

2Thank You

ANSWER

What in impedence

Posted by Shivam Sagar 7 years, 2 months ago

CBSE > Class 12 > Physics

1 answers

Satyam Kumar 7 years, 2 months ago

The total effective resistance offered by LCR circuit is called impedance

2Thank You

ANSWER

What is the difference between diffraction and scattering?

Posted by Parakram Singh Chauhan 4 years, 6 months ago

CBSE > Class 12 > Physics

1 answers

Sia ? 4 years, 6 months ago

• Diffraction is a phenomenon observed only in waves, but scattering is a phenomenon observed in both waves and particles.

• Diffraction is a property of propagation of waves, whereas scattering is a property of wave interactions.

• Diffraction can be taken as evidence for the wave nature of light. Some forms of scattering (Compton scattering) can be taken as evidence for the particle nature of light.

0Thank You

ANSWER

Drive len maker formula

Posted by Hamza Mughal 7 years, 2 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Discuss Coulombs law in vector form

Posted by Sonu Kumar 7 years, 2 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

What is the principal of mutual induction.

Posted by Satyam Kumar 7 years, 2 months ago

CBSE > Class 12 > Physics

1 answers

Aisha Gupta 7 years, 2 months ago

It means an EMF is induced in a coil when a changing current flows through its nearby coil

3Thank You

ANSWER

Can there be a magnet with: a. No poles b. 3 poles ???????

Posted by Tamoghna Roy 7 years, 2 months ago

CBSE > Class 12 > Physics

6 answers

Hy Shona 7 years, 2 months ago

It is poles not loles sorry

1Thank You

Hy Shona 7 years, 2 months ago

Deepak i also want to know about three loles existence.and mono poles mr roy

1Thank You

Saumya Tripathi 7 years, 2 months ago

Deepak.jindal .can u elaborate...I want to know more about the existance of three poles. If u plzzz..

1Thank You

Tushar Jaryal 7 years, 2 months ago

But no pole can't be exist

1Thank You

Tushar Jaryal 7 years, 2 months ago

Deepak , monopoles can also exist ...scientists have also make it possible

1Thank You

Deepak Jindal 7 years, 2 months ago

Yss, there can be a magnet with 3 poles ... But there is no magnet which has no poles..

3Thank You

ANSWER

Explain the derivation of dimension formula of stefan constant

Posted by Naveen Yadav Yadav 7 years, 2 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

An oil drop of mass m and charge -q is to held stationery in the gravitational field of the earth. What is the magnitude and direction of the electrostatic field required for this purpose?

Posted by Abhishek Jadav 7 years, 2 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Numerical by dinesh of 11th

Posted by Nitish Singh 7 years, 2 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

A double Convex lens made from a material of refractive index meu1 in a liquid of refractive index meu2>meu1.what change,if any would occur on the nature of lens.

Posted by Saraswati Sharma 7 years, 2 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

How to change galvanometer into ameter.

Posted by Satyam Kumar 7 years, 3 months ago

CBSE > Class 12 > Physics

3 answers

G K 7 years, 2 months ago

s = (Ig×G)/(I-Ig)....s=shunt resistance , Ig=full scale deflection , G=resistance of galvanometer , I=new range of ammeter...

0Thank You

Satyam Kumar 7 years, 2 months ago

Please give me specific formula for that

0Thank You

G K 7 years, 2 months ago

Since Galvanometer is a very sensitive instrument...... therefore it can't measure heavy currents..... In order to convert a Galvanometer into an Ammeter, .....a very low resistance known as "shunt" resistance is connected in parallel to Galvanometer. Value of shunt is so adjusted that most of the current passes through the shunt....

2Thank You

ANSWER

Why terminal potential difference is less than emf?

Posted by Aastha Sharma 7 years, 3 months ago

CBSE > Class 12 > Physics

3 answers

Aastha Sharma 7 years, 2 months ago

Thanks both of u

0Thank You

G K 7 years, 3 months ago

Because emf is the potential difference across the two terminals of a voltage source when it is not connected to any circuit...... And once it is connected to a circuit, the voltage reduces slightly....... because of the internal resistance of the voltage source.

4Thank You

Ritik Kakan 7 years, 3 months ago

Because there is potenial drop in terminal p.d

1Thank You

ANSWER

Drift velocity derrivation and numericals

Posted by Lakshay Choudhary 7 years, 3 months ago

CBSE > Class 12 > Physics

1 answers

Satyam Kumar 7 years, 3 months ago

During conduction the velocity of free electron changes the avg.velocity of free electron during succesive collision is called drift velocity. It is derive as [vd=V1+V2+V3+V4...../n] Where n is the no.of collision

2Thank You

ANSWER

Determine refractive index of a substance if critical angle is 45degree

Posted by Mohit Sepat 7 years, 3 months ago

CBSE > Class 12 > Physics

6 answers

Amandeep Kumar 7 years, 3 months ago

Sin Ic = 1/ mue Sin 45 = 1/√2 Hence mue = √2 = 1.414

0Thank You

Rahul Singh 7 years, 3 months ago

1.414

0Thank You

Rahul Singh 7 years, 3 months ago

0.414

1Thank You

G K 7 years, 3 months ago

Root2

0Thank You

Mohit Sepat 7 years, 3 months ago

What does it mean

0Thank You

Prince Kumar 7 years, 3 months ago

I donothaveregistered

0Thank You

ANSWER

What type of lenses is a tumbler filled with water???

Posted by Mohit Sepat 7 years, 3 months ago

CBSE > Class 12 > Physics

2 answers

Mohit Sepat 7 years, 2 months ago

Why convex lens

0Thank You

Sreya Bhanja 7 years, 3 months ago

Convex lens

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ANSWER

What happen to the focal length of a convex lens when it is immersed in water??

Posted by Mohit Sepat 7 years, 3 months ago

CBSE > Class 12 > Physics

4 answers

Mohit Sepat 7 years, 2 months ago

One time u say that f will increase and one time decrease .....final ur answer

1Thank You

G K 7 years, 2 months ago

When a lens is immersed in water, the value of refractive index decreases. Hence its focal length increases.

0Thank You

Mohit Sepat 7 years, 2 months ago

How u can say that focal length will decrease

1Thank You

G K 7 years, 3 months ago

Focal length decreases.....

0Thank You

ANSWER

The surfaces of the sun glass are curved ,yet their power may be zero ...Why??

Posted by Mohit Sepat 7 years, 3 months ago

CBSE > Class 12 > Physics

1 answers

Srivinayak V 7 years, 3 months ago

A sunglass is made up of two glasses ie ,one convex and a concave lens of same radius of curvature and same focal length. So they posses same power in two structures. Power of concave lens = -xD Power of convex lens = -xD. Therefore power of combination of lens = 0

1Thank You

ANSWER

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