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

Hi Simmi Sharma!! It's simple if you are perfect in series and parallel combination. See, you need to find out how many capacitors/condensers are needed to make effective of (20uf,440uf). You need to increase the voltage rating 2 times in series(voltage varies in series combinatin). So, 1/c= 1/20+1/20 > C=10uf In series combination it is (10uf,440V). To have capacitance of 40uf you should connect 4 such in parallel combination (Ceff. =Sum of each capacitance) So, no.of capacitors=n×m = 2 nos.for each series combination× 8such parallel combination. = 16 capacitors:-):-):-)

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A charge q is placed at the centre of the line joining two equal charges Q . Show that the system of three charges will be in euilibrium if q=-Q/4

Posted by Sandeep Vishwakarma 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Gaurav Seth 6 years, 4 months ago

Suppose the three charges be placed as shown in the figure.

As, the net force on q is zero, so it is already in equilibrium. For equilibrium of other two charges-, the net force on each charge must be zero.

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Why current is a scaler quantity???

Posted by Mohini Singh 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Satyam Yadav 6 years, 4 months ago

Hello.. Mohini Dalwal..Yes, the current has both direction and magnitude both but we call it scalar quantity because the direction in which the current flows same. ... electric current doesnot obey vector law of addition and multiplication .

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two wires of different metals but of equal lengths have their radii in the ratio of4:3. if the ratio of their resistivities is 4:1 and the resistance of thicker wire is 4.5 ohm. find resistance of thinner wire

Posted by Nehanoor Bhutani 6 years, 4 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Is ohm's law always followed by metallic conductor....?????????

Posted by Prakhar J 6 years, 4 months ago

CBSE > Class 12 > Physics

4 answers

Deepak Jindal 6 years, 4 months ago

Noo

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Aiman Naaz 6 years, 4 months ago

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Pawan Tripathi 6 years, 4 months ago

Yes

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Anuj Dubey 6 years, 4 months ago

No..

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How does the random motion of free electrons in a conductor gets affected when a potential difference is applied on it's end.....?????

Posted by Prakhar J 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Nishu Sahu 6 years, 4 months ago

When p.d is applied the free e- are attracted to +ve terminal and repel by -ve terminal of battery or cell. By this way all e- moves in one direction -ve to +ve.

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What is capacitor and how it is different from resistor

Posted by Sachin Kumar 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Ujjawal Yadav 6 years, 4 months ago

A capacitor is a device which is to store the charge in the form of magnetic field and resistor is a a device which is used to store the charge in the form of electric field ok

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Which is the most difficult chapter in physics?

Posted by Arushi Jaiswal 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Deepak Jindal 6 years, 4 months ago

Unit 4

1Thank You

Ujjawal Yadav 6 years, 4 months ago

Electrostatic

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Why there is no way to sperate the internal resistance and E.M.F of cell

Posted by Preet Komal 6 years, 4 months ago

CBSE > Class 12 > Physics

0 answers

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A charge Q is distributed over two concentric hollow sphere of radiir and R such that the surface charge densities are equal. Find the potential at the common center

Posted by Rohit Vinayak 6 years, 4 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

Define electric flux write its SI unit

Posted by Gajendra Kumar 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Deepak Singh Rautela 6 years, 4 months ago

In simple way -no. Of field lines passing through closed surface.

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Sinchana Malagond 6 years, 4 months ago

The no.of lines entering through a given surface is electric flux OR rate of flow of electric field through a given surface. Its SI unit is Vm. OR Nm^2C^-1

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What is the amount of work done in moving a point charge Q around a circular Arc at the centre at which another point charge Q is located

Posted by Gajendra Kumar 6 years, 4 months ago

CBSE > Class 12 > Physics

0 answers

ANSWER

culambs low

Posted by Gamish Yadav 5 years, 5 months ago

CBSE > Class 12 > Physics

1 answers

Karan Kumar 6 years, 4 months ago

The force of interaction between the two stationary point charges in vaccum is directly proportional to product of two charges and inversely proportional to the square of the distance between them. This is known as coloumb's law. i.e. F=kq1.q2/r*r. I hope you understood. ???

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2019 to 2020 sample released date coming up are not

Posted by Kartik Sawroop 6 years, 4 months ago

CBSE > Class 12 > Physics

0 answers

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How much amont of charge on a cup??

Posted by Alam Sadab 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Darshna T 6 years, 4 months ago

If full then there would be 250ml of water

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Darshna T 6 years, 4 months ago

Half cup or full

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11. Calculate the electric field strength required to just support a water drop of mass 10-7kg and having a charge 1.6 x10-19C. Ans. E=6.125x1012N/C.

Posted by Dhairya Sharma 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Alam Sadab 6 years, 4 months ago

E= mg/q Putting values then u will find the answer

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What is difference between potential and potential difference

Posted by Ravi Yadav 6 years, 4 months ago

CBSE > Class 12 > Physics

2 answers

Paro D 6 years, 4 months ago

POTENCIAL : is the work done to bring a unit positive charge from infinity to that point from external electric field While POTENCIAL DIFFERENCE. is the work done to bring a unit positive charge in internal electric field

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Dhairya Sharma 6 years, 4 months ago

The potential at any point is the amount of workdone to be done to bring a test charge from infinity to that point against the electric field whereas the potential difference is simply the difference of potential at 2 different points. E.g. let a point be A where the potential is 10 and other point be B where the potential is 7, so the potential difference of the system is 10-7=3Volt.

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find potential due to non conducting solid sphere whose volume chare density is row

Posted by K Kumar 6 years, 4 months ago

CBSE > Class 12 > Physics

0 answers

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Two slit in young's interference hae width ratio of 1:16 reduce the intensity at maxima and minima at interference pattern

Posted by Baby Wangsu 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Baby Wangsu 6 years, 4 months ago

25/9

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Consider three charges q1,q2,q3,each equal to q at vertices of an equilateral triangle of side l .what is the force on charge Q with same sign as q placed at the centroid of the triangle?

Posted by A A 6 years, 4 months ago

CBSE > Class 12 > Physics

1 answers

Gaurav Seth 6 years, 4 months ago

Consider three charges q₁ q₂, q₃, each equal to q at the vertices of an equilateral triangle of side l. What is the force on a charge Q (with the same sign as q) placed at the centroid of the triangle, as shown in the figure on the next page?