## Practice paper for AHSEC class 12 on Magnetic effect and Magnetic properties

Total marks 25    Total time-1hour

Set A (each question carries one mark)

01. What is 1 tesla?

02. Give the dimensional formula of permeability

03. What is the resonance condition of  cyclotron?

04. What is an ideal voltmeter?

05. State gauss law in magnetism.

Set B (its question carries 2 marks)

01. How a galvanometer can be converted into an ammeter? Explain with diagram

02. Define the magnetic elements of earth

03. Find expression for torque acting on a bar magnet placed in a uniform magnetic field

04. Give the difference between diamagnetic and paramagnetic substance

Set C(Each question carries 3 marks)

01. Using ampere’s circuital law find expression for magnetic field due to solenoid.

02. Find expression for magnetic field at the axial point of  a current loop

03. Find the expression for force acting between two parallel current carrying conductor in the same direction.

04. Find expression for magnetic moment due to an revolving electron what is Bohr magneton?

## Practice paper for class 12 AHSEC : 2020

1. Total marks-25  Total time-1hour

Set A(Each question carries 1 mark)

01. Write down the properties of electric charge

02. Draw the diagram of electric lines of force due to thin sheet of charge

03. What is an equipotential surface?

04. Give the resistance of a resistor with colour code of red black green silver

05. How mobility of charge carriers is related to temperature?

Set B(Each question carries 2 marks)

01. Give the difference between polar and nonpolar dielectrics.

02. find the expression for torque acting on an electric dipole placed in a uniform electric field.

03. Explain the two laws of kirchoff laws with diagram

04 . Find the expression for capacitance of parallel plate capacitor

Set C(each question carries 3 marks)

01. Express coulomb’s law in vector form

02. Using gauss theorem find an expression for electric field due to the hollow sphere at a point outside and  on its surface

03. Find expression for electric potential due to an electric dipole at any point

04. Using the concept of drift velocity establish ohm’s law

## Practice paper for AHSEC class 12 of 2020

Total mark -36

Total time -90 minutes

Each question carries carries 3 marks

Q1- Obtain the relation between angle of minimum deviation for a prism and its refractive index .

Q2- Draw the ray diagram for reflecting type telescope . Write down advantages of reflecting type telescope over refracting type telescope .

Q3- define critical angle  . Write down the condition for total internal reflection .What is optical fibre .

Q4-Write down Huygens principles . Draw the diagram for wavefront  due to a point source.

Q5- Prove that for destructive interference path difference between the two light waves should be odd integral multiple of λ/ 2.

Q6- State Malus law . Prove that when light is incident at polarising angle on a reflecting surface angle between reflected and refracted light is 90 º

Q7- Draw a ray diagram for Davission and Germer  experiment . Write down few uses of de Broglie’s hypothesis.

Q8- State Bohr’s postulate  . Write down its failures .

Q9- Draw and explain binding energy curve.

Q10-  Explain the working of zener diode as voltage regulator

Q11- Give the Boolean expression and truth table of NAND gate . How OR gate can be obtained from NOR gate and NAND gate ?

Q12- Define the following terms :-  noise , attenuation and modulation .

## SAMPLE PAPERS / 2019 / AHSEC / XII / PHYSICS / NO.-01

SAMPLE PAPER 2019_A

## HS XII Electrostatics year-wise questions

2019

1. Mention one similarity between Coulomb force and gravitational force acting  between two stationary charges. [Mark-1]
2. Define one coulomb charge. Two point charges at a distance r in air exert a force F on each other. At what distance will these charges experience the same force F in a medium of dielectric constant k ? [Mark-1+1=2]
3. There is an electric dipole on the x-y plane. Its dipole moment is 4 x 10-9Cm . On the same plane there is also a uniform electric field  of magnitude 5 x 104 N/C . If the axis of the dipole makes an angle 300 with the electric field, calculate the magnitude ot the torque acting on the dipole and also mention the direction of torque [Mark-2+1=3]
4. The capacity of a parallel plate capacitor with air is 18 pF.  When a dielectric material is inserted in the space between the plates, its capacity becomes  108 pF. Calculate the permittivity of the material. What is the material ?  [Mark-2+1=3]

2018

1. Which experiment established the fact that electric charge is quantized ? [Mark-1]
2. Give the statement of Coulomb’s law for the force between two point charges. Write this law in vector notation for two point charges of same magnitude and opposite sign separated by a distance r in vacuum. [Mark-1+1=2]          (or)
3. Two point charges 0.01/μC and -0.01/μC are placed 10cm apart in vacuum. Calculate the magnitude of electric field intensity at the middle point of the line joining the charges and mention its direction.           [Mark-1+1=2]
4. Apply Gauss’s law to derive the expression for electric field intensity due to an infinitely long straight uniformly charged wire. What is the direction of the field intensity if it is positively charged ?                     [Mark-2+1=3]       (or)
5. Derive the expression for field intensity due to an electric dipole in vacuum for points on its axis. Compare the variation of field intensity with distance for an electric dipole and a point charge when both are kept in vacuum. [Mark-2+1=3]
6. A 600μF capacitor is charged by a 200V supply. It is then disconnected from the supply and is connected to another uncharged 600μF capacitor. How much electrostatic energy is lost in the process ?    [Mark-3]
7. In the diagram below , a particular of mass  “m” and charge (-q) initially moving along X-axis with velocity “vx” enters the region between two charged plates. The length of the plate system is “L” and uniform electric field between the plates is “E”. What is the vertical deflection of the particle at the far edge of the plate ? [Mark-3]

2017

1.      The product of permeability of free space and permitivity is —
(Choose the right option)
(i) c              (ii) c-1              (iiij c2                (iv )c-2    where c is velocity of light. [Mark-1]
2. In an electric field a unit positive charge is displaced from one point to another point along a straight line of length 2 cm and the work done is 2mJ . If it is displaced along a parabolic path . between the same points of length 5 cm, what will be the work done ?    [Mark-1]
3. Three electric point charges qo  ,  q1 and q2 are at distances r0, r and r2  respectively with respect to same origin. What is the force on charge q0 in the field of charges q1 and q2 ?[Mark-2]
4. The volume charge density within a volume Vis ρ(r). What is the force on a small test charge q0 placed outside the volume having position vector r0 with respect to the same origin considered to specify the position vector of the charge distribution within the volume. [Mark-2]
5. What is the net electric flux through a closed surface surrounding an electric dipole ? Derive the expressions for electric field intensity both inside and outside a uniformly charged spherical cell. What is the total charge enclosed by a closed surface if the electric flux entering and leaving the
surface are 20000 N/Cm2 and 30000 N/Cm2 respectively. Given∈0= 8.85x 10-12 C2N~1 m 2 .   [Mark-1+3+1=5]                             (or)
6. Why is an insulator sometimes called a dielectric ? What is the main difference between free and bound charge ? Generally one of the two plates of a Capacitor System is earthed, why? Derive the expression for the energy stored in a charged capacitor.           [Mark-1+1+1+2=5]

## Marking pattern for AHSEC Physics ,2019

Assam higher secondary education council announced new marking pattern for the subject physics 2019 . Marking pattern will be same for unit 1 ,unit 3 , unit 4, unit 5, unit 6, unit 7 and unit 9 . For unit 2 and unit 8 , 1 mark is increased  and for unit 10 2 mark is  decreased . Full marking scheme is given below

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