16. Wavelength of light of frequency 100 Hz ?

15. Light enters at an angle of incidence in a transparent rod of refractive index n. For what value of the refractive index of the material of the rod the light once entered into it will not leave it through its lateral face whatsoever be the value of angle of incidence ?

14. An electromagnetic radiation of frequency n, wavelength λ, travelling with velocity v in air enters in a glass slab of refractive index (μ). The frequency, wavelength and velocity of light in the glass slab will be respectively ?

13. Light travels through a glass plate of thickness t and refractive index μ. If c is the speed of light in vacuum, the time taken by light to travel this thickness of glass is ?

12. One face of a rectangular glass plate 6 cm thick is silvered. An object held 8 cm in front of the first face forms an image 12 cm behind the silvered face. The refractive index of the glass is ?

11. A point source of light is placed 4 m below the surface of water of refractive index 5/3. The minimum diameter of a disc, which should be placed over the source, on the surface of water to cut off all light coming out of water is ?

10. Time taken by sunlight to pass through a window of thickness 4 mm whose refractive index is 3/2 is ?

9. A beam of monochromatic light is refracted from vacuum into a medium of refractive index 1.5, the wavelength of refracted light will be ?

8. Green light of wavelength 5460 Å is incident on an air-glass interface. If the refractive index of glass is 1.5 , the wavelength of light in glass would be (c = 3 × $10^8$ $ms^−1$) ?

7. A beam of light from a source L is incident normally on a plane mirror fixed at a certain distance x from the source. The beam is reflected back as a spot on a scale placed just above the source 1. When the mirror is rotated through a small angle θ, the spot of the light is found to move through a distance y on the scale. The angle θ is given by ?

6. Match the corresponding entries of column-1 with column-2 (Where m is the magnification produced by the mirror) :

6. Match the corresponding entries of column-1 with column-2 (Where m is the magnification produced by the mirror) :

5. Two plane mirrors are inclined at $70^◦$ . A ray incident on one mirror at angle θ after reflection falls on second mirror and is reflected from there parallel to first mirror. The value of θ is ?

4. A rod of length 10 cm lies along the principal axis of a concave mirror of focal length 10 cm in such a way that its end closer to the pole is 20 cm away from the mirror. The length of the image is ?

3. A person is six feet tall. How tall must a vertical mirror be if he is able to see his entire length ?

2. If two mirrors are kept inclined at $60^◦$ to each other and a body is placed at the middle, then total number of images formed is ?

1. Ray optics is valid, when characteristic dimensions are ?

CBSE NEET JEE Guidelines for Students and Parents

 

                                                              

Physics is a multi dimensional subject and has to be studied from many different aspects. The purpose of this website is to provide students of class 11, 12 and entrance exam preparers with high quality study materials and useful resources.

Guidelines and FAQs for Students:

For CBSE and State Board exam success: Steps 1, 2, 3 are compulsory. Step 4 good to do.

Step 1: Theory, Concepts, Derivations:
CBSE or State board text books, Handbooks, Chapterwise Study (Useful simulations and collection of videos provided here), Study Notes.

Step 2: Numerical Practice: Examples, Exercises.
Solve the Numerical from your text book. 

Step 3: Numerical Practice: Chapter wise past paper questions
 Any one of the publishers such as Arihant, MTG, XAM Idea.

For Entrance exam success: Steps 4, 5 are compulsory for NEET, JEE Main, VITEEE, Amrita AEEE, KVPY, CUET etc. Step 6 compulsory for IIT aspirants.

Step 4: Numerical Practice: 

Competency Based Questions, Exemplar Questions from NCERT website

Step 5: Numerical Practice: 

Chapterwise NEET Past paper Questions, Chapterwise JEE Main Past paper Questions. 

Chapterwise PDF downloads provided here. Arihant or MTG publications are good.

Step 6: Numerical Practice: 

JEE Advanced Past paper Questions, 

Practice questions from Concepts of Physics, HC Verma.

Above steps can be equally applied for other subjects such as Mathematics, Chemistry and Biology.

How much Physics should I do?
One hour of physics per day,

10 numerical problems per day, 

2 to 3 weeks per chapter, 

Approx. 100 problems per chapter,

Approx. 14 chapters in one year of class 11, 

Approx. 14 chapters in one year of class 12.

Do I need a teacher to learn Physics?

Starting from Galileo and then Newton, Faraday, Edison, Tesla, Einstein, CV Raman, we have some 400 years of Physics discoveries packed into two years of 11th, 12th and entrance exam preparation. You can study from your school teacher alone. It is possible. But most students will need a tutor to help you with your difficulties initially.

How to study Physics?

You can study Physics from everywhere. Sometimes from a teacher, sometimes from textbooks, handbooks, sometimes from videos and interactive simulations, sometimes from doing some simple experiments in your home or your school, sometimes from your friend, sometimes from solving numerical problems, sometimes from nature, sometimes while going in a car or train. Physics is all around you. You just have to keep your eyes open.

Physics and Mathematics?

Physics and Mathematics are like twin sisters. They always come together. While the first part of any numerical solving is formulating the problem using Physics concepts, the second part is always mathematical simplification using Drawings, Graphs, Algebra, Trigonometry, Differentiation, Integration, Vectors etc.

Newton was not able to solve some Physics problems and he had to invent a new stream of Mathematics called Integral Calculus.

Mathematics is the language of mother nature. Physics is all about studying the nature. That's why it was called as Natural Philosophy.

Why do I have to study Physics?

Physics is the foundation for all Engineering and Science majors in college such as Mechanical, Aeronautical, Electrical, Electronics, Structural, Nuclear Engineering, Architecture, Integrated M.Sc. Physics, Energy Physics, Applied Physics, Photonics, Reactor Physics, Biophysics etc.

Students with proper physics foundation, do very well in Engineering majors. Engineering is all about problem solving. So get used to physics problem solving if you are planning to get into Engineering.

I find Physics problems very difficult?

Everything is difficult, before it becomes easy. Just like any other skills such as swimming, driving, speaking new language, Physics is also difficult to begin with.

"Remember, no problem is difficult. Once you understand the theory, each problem will become easy." - Dr. H.C. Verma

I am afraid. I make lot of mistakes?

Newton has made lot of mistakes. Einstein has made lot of mistakes. The good news is we are all allowed to make mistakes and then correct them. It's the first step to arrive at a solution.

For the Love of Physics

The capacitance of a parallel plate capacitor with air as medium is 6μF. With the introduction of a dielectric medium, the capacitance becomes 30μF. The permittivity ?

Two identical capacitors C1 and C2 of equal capacitance are connected as shown in the circuit. Terminals a and b of the key k are connected to charge capacitor C1 using battery of emf V volt. Now disconnecting a and b the terminals b and c are connected. Due to this, what will be the percentage loss of energy ?

The electrostatic force between the metal plates of an isolated parallel plate capacitor C having a charge Q and area A, is ?

A capacitor is charged by a battery. The battery is removed and another identical uncharged capacitor is connected in parallel. The total electrostatic energy of resulting system ?

A capacitor of 2μF is charged as shown in the diagram. When the switch S is turned to position 2 , the percentage of its stored energy dissipated is ?

A parallel plate air capacitor of capacitance C is connected to a cell of emf V and then disconnected from it. A dielectric slab of dielectric constant K, which can just fill the air gap of the capacitor, is now inserted in it. Which of the following is incorrect ?

A parallel plate air capacitor has capacity ’ C ’ distance of separation between plates is ’ d ’ and potential difference ’ V ’ is applied between the plates. Force of attraction between the plates of the parallel plate air capacitor is ?

Two thin dielectric slabs of dielectric constants K1 and K2 ( K1 < K2) are inserted between plates of a parallel plate capacitor, as shown in the figure. The variation of electric field ’E’ between the plates with distance ’d’ as measured from plate P is correctly shown by ?

A parallel plate capacitor has a uniform electric field E in the space between the plates. If the distance between the plates is d and area of each plate is A, the energy stored in the capacitor is ?

A series combination of n_1 capacitors, each of value C1, is charged by a source of potential difference 4 V. When another parallel combination of n2 capacitors, each of value C2. is charged by a source of potential difference V , it has the same (total) energy stored in it, as the first combination has. The value of C2, in terms of C1, is then ?

Two parallel metal plates having charges +Q and −Q face each other at a certain distance between them. If the plates are now dipped in kerosene oil tank, the electric field between the plates will ?

Three capacitors each of capacitance C and of breakdown voltage V are joined in series. The capacitance and breakdown voltage of the combination will be ?

Two condensers, one of capacity C and other of capacity C/2 are connected to a V -volt battery, as shown. The work done in charging fully both the condensers is ?

A parallel plate air capacitor is charged to a potential difference of V volts. After disconnecting the charging battery the distance between the plates of the capacitor is increased using an insulating handle. As a result the potential difference between the plates ?

A network of four capacitors of capacity equal to C1 = C , C2 = 2C , C3 = 3C and C4 = 4C are connected to a battery as shown in the figure. The ratio of the charges on C2 and C4 is ?

Three capacitors each of capacity 4μF are to be connected in such a way that the effective capacitance is 6μF. This can be done by ?

A capacitor C_1 is charged to a potential difference V. The charging battery is then removed and the capacitor is connected to an uncharged capacitor C_2. The potential difference across the combination is ?

In a parallel plate capacitor, the distance between the plates is d and potential difference across the plates is V. Energy stored per unit volume between the plates of capacitor is ?

The capacity of a parallel plate condenser is 10μF when the distance between its plates is 8 cm. If the distance between the plates is reduced to 4 cm then the capacity of this parallel plate condenser will be ?

Energy stored in a capacitor is ?

A capacitor is charged to store an energy U. The charging battery is disconnected. An identical capacitor is now connected to the first capacitor in parallel. The energy in each of the capacitor is ?

A parallel plate condenser with oil between the plates (dielectric constant of oil K = 2 ) has a capacitance C. If the oil is removed, then capacitance of the capacitor becomes ?

What is the effective capacitance between the points X and Y ?

If the potential of a capacitor having capacity 6μF is increased from 10 V to 20 V, then increase in its energy will be ?

The four capacitors, each of 25μF are connected as shown in fig. The dc voltmeter reads 200 V. The charge on each plate of capacitor is ?

A 4μF conductor is charged to 400 volts and then its plates are joined through a resistance of 1kΩ. The heat produced in the resistance is ?

The potential energy of particle in a force field is U = A / r^2 − B / r , where A and B are positive constants and r is the distance of particle from the centre of the field. For stable equilibrium, the distance of the particle is ?

Three charges, each +q, are placed at the corners of an isosceles triangle ABC of sides BC, AC and AB, D and E are the mid points of BC and CA. The work done in taking a charge Q from D to E is ?

Charges +q and −q are placed at points A and B respectively which are a distance 2L apart, C is the midpoint between A and B. The work done in moving a charge +Q along the semicircle CRD is ?

As per the diagram, a point charge +q is placed at the origin O. Work done in taking another point charge −Q from the point A[ coordinates (0, a)] to another point B [coordinates (a, 0)] along the straight path AB is ?

Two charges q1 and q2 are placed 30 cm apart, as shown in the figure. A third charge q3 is moved along the arc of a circle of radius 40 cm from C to D. The change in the potential energy of the system is q3/4πε0 k, where k is ?

An electric dipole has the magnitude of its charge as q and its dipole moment is p. It is placed in uniform electric field E. If its dipole moment is along the direction of the field, the force on it and its potential energy are respectively ?

A bullet of mass 2 g is having a charge of 2μC. Through what potential difference must it be accelerated, starting from rest, to acquire a speed of 10 m/s ?

Each corner of a cube of side l has a negative charge, −q. The electrostatic potential energy of a charge q at the centre of the cube is ?

A particle of mass m and charge q is placed at rest in a uniform electric field E and then released. The kinetic energy attained by the particle after moving a distance y is ?

In a certain region of space with volume 0.2 m^3 , the electric potential is found to be 5 V throughout. The magnitude of electric field in this region is ?

A short electric dipole has a dipole moment of 16 × 10^−9Cm. The electric potential due to the dipole at a point at a distance of 0.6 m from the centre of the dipole, situated on a line making an angle of 60◦ with the dipole axis is ?

The diagrams below show regions of equipotentials. A positive charge is moved from A to B in each diagram.

If potential (in volts) in a region is expressed as V (x, y, z) = 6xy − y + 2yz, the electric field (in N/C ) at point (1, 1, 0) is ?

In a region, the potential is represented by V (x, y, z) = 6x − 8xy − 8y + 6yz, where V is in volts and x, y, z are in metres. The electric force experienced by a charge of 2 coulomb situated at point (1, 1, 1) is ?

A conducting sphere of radius R is given a charge Q. The electric potential and the electric field at the centre of the sphere respectively are ?

A, B and C are three points in a uniform electric field. The electric potential is ?

Four point charges −Q, −q, 2q and 2Q are placed, one at each corner of the square. The relation between Q and q for which the potential at the centre of the square is zero is ?

Four electric charges +q, +q, −q and −q are placed at the corners of a square of side 2 L (see figure). The electric potential at point A, midway between the two charges +q and +q, is ?

Three concentric spherical shells have radii a, b and c (a < b < c) and have surface charge densities σ, −σ and σ respectively. If VA, VB and VC denotes the potentials of the three shells, then for c = a + b, we have ?

The electric potential at a point (x, y, z) is given by V = −(x^2)y − x(z^3) + 4. The electric field E at that point is ?

The electric potential at a point in free space due to a charge Q coulomb is Q × 10^11 volts. The electric field at that point is ?

A solid spherical conductor is given a charge. The electrostatic potential of the conductor is ?

A hollow metal sphere of radius 10 cm is charged such that the potential on its surface is 80 V. The potential at the centre of the sphere is ?

Links

 https://youtube.com/shorts/9ogNw39WQ74?si=ccDRz3Fl1A_RuaFL

Maths( A+B) ^2 illustration

Intensity of an electric field (E) depends on distance r, due to a dipole, is related as ?

The electric potential V at any point (x, y, z), all in meters in space is given by V = 4x2 volt. The electric field at the point (1, 0, 2) in volt/ meter is ?

A charge q is located at the centre of a cube. The electric flux through any face is ?

The formation of a dipole is due to two equal and dissimilar point charges placed at a ?

A sphere encloses an electric dipole with charges ± 3 × 10^−6 C. What is the total electric flux across the sphere ?

The electric field in a certain region is acting radially outward and is given by E = Aa. A charge contained in a sphere of radius ’ a ’ centered at the origin of the field, will be given by ?

What is the flux through a cube of side ’ a ’ if a point charge of q is at one of its corner ?

A charge Q is enclosed by a Gaussian spherical surface of radius R. If the radius is doubled, then the outward electric flux will ?

A square surface of side L meter in the plane of the paper is placed in a uniform electric field E (volt/m) acting along the same plane at an angle θ with the horizontal side of the square as shown in Figure. The electric flux linked to the surface, in units of volt. m, is ?

A hollow cylinder has a charge q coulomb within it. If φ is the electric flux in units of voltmeter associated with the curved surface B, the flux linked with the plane surface A in units of voltmeter will be ?

A square surface of side L metres is in the plane of the paper. A uniform electric field E (volt/m ), also in the plane of the paper, is limited only to the lower half of the square surface (see figure). The electric flux in SI units associated with the surface is ?

A charge QμC is placed at the centre of a cube, the flux coming out from any surface will be ?

A charge Q is placed at the comer of a cube. The electric flux through all the six faces of the cube is ?

A point charge +q is placed at mid point of a cube of side ’L’. The electric flux emerging from the cube is ?

A spherical conductor of radius 10 cm has a charge of 3.2 × 10−7C distributed uniformly. What is the magnitude of electric field at a point 15 cm from the centre of the sphere ?

Two parallel infinite line charges with linear charge densities +λC/m and −λC/m are placed at a distance of 2R in free space. What is the electric field mid-way between the two line charges ?

A hollow metal sphere of radius R is uniformly charged. The electric field due to the sphere at ?

An electron falls from rest through a vertical distance h in a uniform and vertically upward directed electric field E. The direction of electric field is now reversed, keeping its magnitude the same. A proton is allowed to fall from rest in it through the same vertical distance h. The time of fall of the electron, in comparison to the time of fall of the proton is ?

A toy car with charge q moves on a frictionless horizontal plane surface under the influence of a uniform electric field E. Due to the force qE , its velocity increases from 0 to 6 m/s in one second duration. At that instant the direction of the field is reversed. The car continues to move for two more seconds under the influence of this field. The average velocity and the average speed of the toy car between 0 to 3 seconds are respectively ?

An electric dipole of dipole moment p is aligned parallel to a uniform electric field E. The energy required to rotate the dipole by 90◦ is ?

An electric dipole of moment p ′ is placed in an electric field of intensity ’ E ’. The dipole acquires a position such that the axis of the dipole makes an angle θ with the direction of the field. Assuming that the potential energy of the dipole to be zero when = 90◦ , the torque and the potential energy of the dipole will respectively be: ?

The electric field at a distance 3R/2 from the centre of a charged conducting spherical shell of radius R is E. The electric field at a distance R/2 from the centre of the sphere is ?

The mean free path of electrons in a metal is 4×10−8 m. The electric field which can give on an average 2eV energy to an electron in the metal will be in units of V/m ?

If a copper wire is stretched to make its radius decrease by 0.1%, then the percentage increase in resistance is approximately

A thin conducting ring of radius R is given a charge +Q. The electric field at the centre O of the ring due the charge on the part AKB of the ring is E. The electric field at the centre due to the charge on the part ACDB of the ring is ?

Three point charges +q, −q and +q are placed at points (x = 0, y = a, z = 0),(x = 0, y = 0, z = 0) and (x = a, y = 0, z = 0) respectively. The magnitude and direction of the electric dipole moment vector of this charge assembly are ?

Two steel wires having the same length are suspended from a ceiling under the same load. If the ratio of their energy stored per unit volume is 1:4, the ratio of their diameters is

The electric intensity due to a dipole of length 10 cm and having a charge of 500μC, at a point on the axis at a distance 20 cm from one of the charges in air, is ?

If a dipole of dipole moment p is placed in a uniform electric field E, then torque acting on it is given by ?

If a dipole of dipole moment \( \vec{p} \) is placed in a uniform electric field \( \vec{E} \), then the torque acting on it is given by ?

<p>(a) \( \vec{\tau} = \vec{p} \cdot \vec{E} \)</p>

<p>(b) \( \vec{\tau} = \vec{p} \times \vec{E} \)</p>

<p>(c) \( \vec{\tau} = \vec{p} + \vec{E} \)</p>

<p>(d) \( \vec{\tau} = \vec{p} - \vec{E} \)</p>

Answer :  <p>(b) \( \vec{\tau} = \vec{p} \times \vec{E} \)</p>

A semi-circular arc of radius ’ a ’ is charged uniformly and the charge per unit length is λ. The electric field at the centre of this arc is ?

A hollow insulated conduction sphere is given a positive charge of 10μC. What will be the electric field at the centre of the sphere if its radius is 2 metres ?

A point Q lies on the perpendicular bisector of an electrical dipole of dipole moment p. If the distance of Q from the dipole is r (much larger than the size of the dipole), then the electric field at Q is proportional to ?

From a point charge, there is a fixed point A. At A, there is an electric field of 500 V/m and potential difference of 3000 V. Distance between point charge and A will be ?

An electric dipole, consisting of two opposite charges of 2 × 10−6C each separated by a distance 3 cm is placed in an electric field of 2 × 105 N/C. Torque acting on the dipole is ?

There is an electric field E in X-direction. If the work done on moving a charge of 0.2C through a distance of 2 m along a line making an angle 60◦ with x-axis is 4 J, then what is the value of E ?

Two point charges A and B, having charges +Q and −Q respectively, are placed at certain distance apart and force acting between them is F. If 25% charge of A is transferred to B, then force between the charges becomes: ?

Two metal spheres, one of radius R and the other of radius 2R respectively have the same surface charge density σ. They are brought in contact and separated. What will be the new surface charge densities on them ?

Suppose the charge of a proton and an electron differ slightly. One of them is - e, the other is (e + ∆e). If the net of electrostatic force and gravitational force between two hydrogen atoms placed at a distance d (much greater than atomic size) apart is zero, then ∆e is of the order of [Given mass of hydrogen mh = 1.67 × 10−27 kg ] ?

If the work done is stretching a wire by 1 mm is 2 J, the work necessary for stretching another wire of same material but with double the radius of cross section and half the length by 1 mm is

Two identical charged spheres suspended from a common point by two massless strings of lengths l, are initially at a distance d(d ≪ l) apart because of their mutual repulsion. The charges begin to leak from both the spheres at a constant rate. As a result, the spheres approach each other with a velocity v. Then v varies as a function of the distance x between the spheres, as: ?

Two pith balls carrying equal charges are suspended from a common point by strings of equal length. The equilibrium separation between them is r. Now the strings are rigidly clamped at half the height. The equilibrium separation between the balls now become ?

A charge ’ q ’ is placed at the centre of the line joining two equal charges ’ Q ’. The system of the three charges will be in equilibrium if ’ q ’ is equal to ?

Two metallic spheres of radii 1 cm and 3 cm are given charges of −1 × $10^{−2}$C and 5 × $10^{−2}$C, respectively. If these are connected by a conducting wire, the final charge on the bigger sphere is ?