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

r= h tan ić...... ......mu=1/sin ić....... ......Sin ić=1/mu=1/1.33=0.75...... ......Now, r=h sin ić/cos ić...... =h sin ić/ (1-sin^2 ić) = 80×10^-2 × 0.75/(1-sin 0.75^2).... r=0.91cm.... Area covered by light, A=pi r^2...... A= 3.14× 0.91^2...... = 2.6m

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What is the wave theory of light

Posted by Siddharth Verma 7 years ago

CBSE > Class 12 > Physics

1 answers

Dipankar Kundu 7 years ago

The free electrons at the surface of the metal absorb the radiant energy continuously.E=hn

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Which are best chapter to score a pass mark

Posted by Abhishek Sharma 7 years ago

CBSE > Class 12 > Physics

1 answers

Pooja Bhatia 7 years ago

Most easiest chapters are :- 1. Current electricity 2. Magnetism and Matter 3. Electromagnetic waves 4. Ray optics 5. Dual nature of matter( if you are good in chemistry) 6. Atoms and Nuclei ...............Note: these all chapters constitute of 28 marks out of 70 and if you wanna pass then you have score more than 24 atleast

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Which chapters are important for numericals in boards?

Posted by Ishika Agarwal 7 years ago

CBSE > Class 12 > Physics

1 answers

Pooja Bhatia 7 years ago

Current electricity, A.C, Ray and wave optics and whole modern physics

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Gauss therom

Posted by Avi Singh 7 years ago

CBSE > Class 12 > Physics

2 answers

Pooja Bhatia 7 years ago

Integration{E⋅da}=Qenc/ϵ0

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Pooja Bhatia 7 years ago

The net electric flux through any hypothetical closed surface is one by absalen times the net electric charge within that closed surface

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35. A source of alternating emf of frequency 50Hz is connected in series with a resistance of 200 Ω, an inductance of 100mH and a capacitance of 30μF. Does the current lead or lag the emf and by what angle?

Posted by Vishmitha Shetty 7 years ago

CBSE > Class 12 > Physics

1 answers

Pooja Bhatia 7 years ago

V=50Hz , w(omega)=2πv=100π....(1) Xc=1/wC=333.34, XL=wL=10.....(2) {If Xc is greater than XL then the current is said to be capacitive causing the current to lead} Tan()= (Xc-XL)/R

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Do any one have Ajmer board question paper in english

Posted by Afiya Ajeeb 7 years ago

CBSE > Class 12 > Physics

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And I need some help. Anyone having notes of Electrostats and Capacitors and Wave Optics, please do tell me. I need it urgently.

Posted by Utsav Aryan 7 years ago

CBSE > Class 12 > Physics

3 answers

Shifali Bijily 7 years ago

Refer notes of Aman daterwal from YouTube

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Kuldeep Singh 7 years ago

Yes I have the notes of all chapters

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Utsav Aryan 7 years ago

Sorry.. it's not capacitor but Transistors

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Relation between threshold frequency, frequency of the incident photon and cutoff potential

Posted by Somya Sen 7 years ago

CBSE > Class 12 > Physics

1 answers

Sanskriti S 7 years ago

eV°=hv-hv°

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The critical angle of incidence in a glass slab placed in aor is 45 degree . what will be the critical angle when it is immersed in water of refractive indec 1.33?

Posted by Chahat Chopra 7 years ago

CBSE > Class 12 > Physics

3 answers

Sanskriti S 7 years ago

70°36'

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Prajjawal Sharma 7 years ago

Sry its wrng

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Prajjawal Sharma 7 years ago

0.107 approx

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3 point charges +2nC ' -5nC and +2nC are placed at the three corners of a square of side 0.2 m in order . calculate the magnitude of the resultant force acting on a point charge ', +1 nC placed at the fourth corner

Posted by Shalet Lobo 7 years ago

CBSE > Class 12 > Physics

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Transformer use

Posted by Sunny Kumar 7 years ago

CBSE > Class 12 > Physics

1 answers

Prajjawal Sharma 7 years ago

For changing high voltage into low and vice versa

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Why there is a phase difference of 180° between the input and output signals in an common emitter transmitter?

Posted by Mahaalakshmi Vijayamoorthy 7 years ago

CBSE > Class 12 > Physics

1 answers

Mahaalakshmi Vijayamoorthy 7 years ago

When there is increase in the base current, simultaneously the collector current increase this increase in collector current, increases the voltage drop across collector. This decreases the voltage at the collector. When there is a increase in the base current there is simultaneous decease in the output voltage or there is phase difference between input and output.

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Reflection from spherical mirrors and find relation between f and r

Posted by Aachman Gupta 7 years ago

CBSE > Class 12 > Physics