Chapter 1: Electric Charges and Fields
Year 2020
A permanent electric dipole of dipole moment p is placed in a uniform external electric field E, as shown in Figure.
(a) Redraw the figure and show the magnitude and direction of force acting on the charges.
(b) Write an expression of the torque acting on this dipole in vector form.
An infinitely long thin straight wire with uniform linear charge density is shown in figure.
(a) Draw a Gaussian surface in order to calculate the electric field at P and mark direction of electric field at this point.
(b) Derive an expression to calculate electric field at this point P.
Year 2021
“The force between two point charges is directly proportional to the product of _______ and inversely proportional to the _______ of the distance between them.”
(a) Define electric dipole moment.
(b) A system has two charges 2.5 × 10⁻⁷ C and –2.5 × 10⁻⁷ C located at points (0, 0, –15 cm) and (0, 0, +15 cm), respectively. Determine the magnitude and direction of electric dipole moment of the system.
(a) Write any two properties of electric field lines.
(b) Observe the figure and write the signs of the charges q₁ and q₂.
Gauss law in electrostatics relates electric flux with electric charge.
(a) Electric flux and electric charge are scalar quantities. State whether this statement is true or false.
(b) State Gauss law in electrostatics.
(c) Using Gauss law derive an expression for the intensity of electric field at a point due to an infinitely long straight uniformly charged wire.
Year 2022
SI unit of electric field.
Electrostatic field at the surface of a charged conductor must be normal to the surface at every point. Is the statement true or false?
(i) State Gauss’s law.
(ii) What is meant by a Gaussian surface?
(iii) Using Gauss’s law, find the electric field due to a uniformly charged thin spherical shell at a point outside the shell.
Year 2023
Two field lines never intersect.
Explain the basic properties of electric charge.
(a) What is an electric dipole?
(b) Obtain the expression for the electric field intensity at a point on the axial line of an electric dipole.
Year 2024
The SI unit of electric flux.
The net electric field inside a conductor when placed in an external electric field is ______.
State and explain the force between electric charges.
Derive the expression for electric field intensity at a point from an infinitely long straight conductor carrying charge.
Year 2025
The electrostatic force per unit charge is known as _____.
(a) Electric current
(b) Electric potential
(c) Electric field
(a) Define electric dipole moment.
(b) Write an expression for torque acting on an electric dipole placed in a uniform electric field. When will it become maximum?
(a) A spherical shell of radius R is uniformly charged with charge +q. Using Gauss’s law find the electric field intensity at a point
(i) Outside the spherical shell
(ii) On the surface of the spherical shell.
(b) A point charge causes an electric flux –2 × 10¹⁴ Nm²/C to pass through a spherical Gaussian surface.
(i) Calculate the value of the point charge.
(ii) If the radius of the Gaussian surface is doubled, how much flux would pass through the surface?
Chapter 2: Electrostatic Potential and Capacitance
Year 2020
How capacitance changes if the distance between the plates of a parallel plate capacitor is halved?
Three capacitors of capacitances 2 pF, 3 pF and 4 pF are connected in parallel.
(a) Write the SI unit of capacitance.
(b) Calculate the effective capacitance of the combination.
(c) Determine the charge on each capacitor if the combination is connected to a 100 V supply.
Year 2021
Calculate the electric potential at a point 9.0 cm away from a point charge of 4 × 10⁻⁷ C.
Derive an expression for the energy stored in a capacitor in terms of capacitance and potential difference across the capacitor.
Write any one difference between polar and non-polar molecule. Give one example each.
(a) Draw a figure of a parallel combination of three capacitors of capacitances C₁, C₂ and C₃.
(b) Derive an expression for the effective capacitance.
Year 2022
Write down any three properties of equipotential surfaces.
SI unit of capacitance is _____. Two capacitors C₁ and C₂ are connected in series. Derive an expression for the capacitance.
Year 2023
(a) Derive the expression for the capacitance of a parallel plate capacitor.
(b) What happens to the capacitance if a medium of dielectric constant K is introduced between the plates?
(a) Give the relation between electric field and potential.
(b) Derive the expression for the potential due to an electric dipole.
(c) Calculate the potential at a point due to a charge of 4 × 10⁻⁷ C located 9 cm away.
Year 2024
What is an equipotential surface? Give an example.
(a) What is the principle of a capacitor?
(b) Derive the expression for capacitance of a parallel plate capacitor.
(c) A 12 pF capacitor is connected to 50 V battery. How much electrostatic energy is stored?
Year 2025
A circle of radius r is drawn with a charge +q placed at the centre. The work done in moving a point charge once around the circumference is _____.
(a) What is equipotential surface?
(b) Write two properties of equipotential surfaces.
(a) Obtain an expression for the equivalent capacitance when two capacitors C₁ and C₂ are connected in parallel.
(b) Given graph shows variation of charge q with potential difference V for two capacitors C₁ and C₂. Both have same plate separation but plate area of C₂ is greater. Which line corresponds to C₁ and why?
Chapter 3: Current Electricity
Year 2020
Three resistors R₁, R₂, R₃ are to be combined as shown in the figures.
(a) Identify the series and parallel combinations.
(b) Which combination has lowest effective resistance?
(c) Arrive at the expression for the effective resistance of parallel combination.
A Wheatstone bridge is shown in figure.
(a) Derive a relation connecting the four resistors for the galvanometer to give zero or null deflection.
(b) Name a practical device which uses this principle.
Year 2021
Draw Wheatstone’s bridge and write its balancing condition.
Determine the value of resistance R in the figure, assuming that the current through the galvanometer (G) is zero.
In the figure shown below
(a) Which are the resistors connected in parallel?
(b) Calculate the current drawn from the cell.
(a) Write the working principle of a potentiometer.
(b) With a neat circuit diagram and with relevant equations explain how the emf of two cells are compared using a potentiometer.
Year 2022
Magnitude of the drift velocity per unit electric field is _____.
A light bulb is rated at 100 W for a 220 V supply. Find the resistance of the bulb.
(i) SI unit of resistance is _____.
(ii) Obtain the equivalent value of resistance when two resistors R₁ and R₂ are connected in series.
Write down the Wheatstone bridge principle.
A meter bridge circuit is given below. Using this circuit, derive an expression for finding the unknown resistance.
In the above circuit, the balance point is found to be at 40 cm from the end A, when the resistance S is 12 Ω. Determine the resistance R.
Would the galvanometer show any current if the galvanometer and cell are interchanged?
Year 2023
The SI unit of resistance is _________.
(a) State Kirchhoff’s law.
(b) Obtain the balancing condition of Wheatstone’s bridge with the help of a diagram.
Year 2024
Define drift velocity, give its equation.
(a) State Ohm’s law.
(b) Derive Wheatstone’s network principle.
Year 2025
Show that the resistance of a conductor can be expressed by
R = ml / ne²τA, where symbols have their usual meanings.
(a) Kirchhoff’s voltage law is in accordance with the conservation of
(i) mass (ii) energy (iii) momentum (iv) charge.
(b) With the help of diagram, arrive at the Wheatstone’s principle.
Chapter 4: Moving Charges and Magnetism
Year 2020
The path of a charged particle entering parallel to uniform magnetic field will be
(a) circular (b) helical (c) straight line (d) None of these.
Ampere’s theorem helps to find the magnetic field in a region around a current carrying conductor.
(a) Write the expression of Ampere’s theorem.
(b) Draw a graph showing the variation of intensity of magnetic field with the distance from the axis of a current carrying conductor.
A rectangular loop of area A and carrying a steady current I is placed in a uniform magnetic field.
(a) Derive the expression of torque, τ = m × B, acting on the loop.
(b) Increasing the current sensitivity may not necessarily increase the voltage sensitivity of a galvanometer. Justify.
Year 2021
State Biot–Savart law and express it mathematically.
Using Ampere’s circuital law show that the intensity of magnetic field at an axial point near the centre of a current carrying solenoid is
B = μ₀nI.
With a circuit diagram explain how a moving coil galvanometer can be converted to an ammeter.
A circular coil of radius R and N turns carries a current I.
Show that the intensity of magnetic field at an axial point distant x from the centre is
B = μ₀NIR² / 2(R² + x²)³ᐟ².
Year 2022
Name the force experienced by a charge q moving through a uniform magnetic field with a velocity V.
(i) What is a solenoid?
(ii) Write down the equation for magnetic field inside a solenoid.
(i) Which law helps us to find the magnetic field on the axis of a circular current loop?
(ii) Consider a tightly wound 100 turn coil of radius 10 cm carrying current of 1 A. What is the magnitude of the magnetic field at the centre?
Year 2023
Current loop behaves as a ________. (Magnetic dipole/Electric dipole)
(a) State Biot–Savart law.
(b) Obtain the expression for the magnetic field on the axis of a circular current loop.
(a) Derive the expression for the torque on a rectangular current loop in a uniform magnetic field with the help of a diagram.
(b) A 100 turn closely wound circular coil of radius 10 cm carries a current of 3.2 A. What is the magnetic moment of this coil?
Year 2024
Figure shows the two current carrying conductors. Derive the expression for force between the conductors.
(a) The direction of magnetic field around a current carrying conductor is given by ______.
(b) State Biot–Savart law.
(c) Derive the expression for magnetic field on the axis of a circular coil carrying current.
Year 2025
(a) What is the working principle of a moving coil galvanometer?
(b) How will you convert a galvanometer into an ammeter?
(c) An ammeter is always connected in series with a circuit. Why?
(a) What is Lorentz force?
(b) The figure shows the path of motion of a charged particle (+q) in a uniform magnetic field.
(i) What will be the direction of magnetic field with respect to the velocity of the charged particle?
(ii) Show that the frequency of revolution of charged particle is independent of the radius of the path.
(iii) Is there any change in kinetic energy of the charged particle? Explain.
Chapter 5: Magnetism and Matter
Year 2020
A magnetised needle in uniform magnetic field experiences a torque but no net force.
An iron nail near a bar magnet, however, experiences a force of attraction in addition to a torque. Why?
What is the magnitude of the equatorial and axial fields due to a bar magnet of length 5.0 cm at a distance of 50 cm from its mid-point?
The magnetic moment of the bar magnet is 0.40 Am².
Year 2021
The expression ∮B · ds = 0 is
(i) Gauss Law in Electrostatics
(ii) Gauss Law in Magnetism
(iii) Ampere’s circuital law
(iv) Lenz’s law.
The behaviour of magnetic field lines near two magnetic substances P and Q are shown below.
(a) From the figure identify paramagnetic substance.
(b) Susceptibility of substance P is _________ (positive/negative).
(a) Define angle of dip.
(b) At a particular place the horizontal and vertical components of earth’s magnetic field are found to be equal. What is the value of dip at this place?
Year 2022
The temperature at which a ferromagnetic material becomes paramagnetic is _____.
(a) Cut-off temperature (b) Absolute temperature (c) Curie temperature.
What is angle of dip?
(i) The angle between magnetic meridian and geographic meridian is _____.
(ii) The declination is _____ (higher/smaller) at higher latitudes and _____ (higher/smaller) near the equator.
Year 2023
Define magnetisation. Give its dimension.
Differentiate between paramagnetic, diamagnetic and ferromagnetic substances.
Year 2024
State Gauss’s law in magnetism.
Compare dia, para and ferromagnetic substances with suitable examples.
Year 2025
Relative permeability of a material μᵣ < 1, identify the magnetic material.
Write the relation between relative permeability and magnetic susceptibility.
(a) State Gauss’s law in magnetism.
(b) A short bar magnet placed with its axis at 30° with a uniform external magnetic field of 0.3 T experiences a torque of magnitude equal to 5 × 10⁻² J. What is the magnitude of the magnetic moment of the magnet?
Chapter 6: Electromagnetic Induction
Year 2020
Coefficient of mutual inductance of two coils is 1 H.
Current in one of the coils is increased from 4 to 5 A in 1 ms. What average emf will be induced in the other coil?
(a) State Faraday's law of electromagnetic induction.
(b) How does the magnetic energy stored in an inductor and electrostatic energy stored in a capacitor relate to their respective field strengths?
Year 2021
Current in a circuit falls from 5.0 A to 0.0 A in 0.1 s.
If an average emf of 200 V is induced, calculate the self-inductance of the circuit.
When bulk pieces of conductors are subjected to changing magnetic flux, currents are induced in them.
(a) Write the name of this induced current.
(b) Write any two practical applications of this current.
(a) Lenz’s law is in accordance with law of conservation of _______.
(b) A jet plane is travelling towards west at a speed of 1800 km/h.
What is the voltage difference developed between the ends of the wing having a span of 25 m, if the vertical component of Earth’s magnetic field at the location is 2.9 × 10⁻⁴ T?
Year 2022
Changing magnetic fields can set up current loops in nearby metal bodies. They dissipate electrical energy as heat. Such currents are _____.
(i) Which is the working principle of an a.c. generator?
(ii) With the help of a diagram explain the working of a.c. generator.
Year 2023
State laws of electromagnetic induction.
(a) State the principle of a.c. generator.
(b) Obtain the expression for the emf generated by an a.c. generator.
Year 2024
What is magnetic flux and how is it measured?
What is self-induction and define the expression for self-inductance of a solenoid.
Year 2025
Which of the following gives the polarity of the induced emf?
(i) Biot-Savart Law (ii) Lenz’s Law (iii) Ampere’s circuital Law (iv) Fleming’s right-hand Rule.
(a) What is the working principle of an a.c. generator?
(b) With the help of a diagram, explain theory and working of an a.c. generator.
Chapter 7: Alternating Current
Year 2020
The current through an AC circuit depends on the magnitude of the applied voltage and impedance of the circuit.
(a) Write any two factors on which the impedance of a series LCR circuit depends.
(b) Draw an impedance diagram of a series LCR circuit and write the expression for the power factor from the diagram.
(c) A sinusoidal voltage of peak value 283 V and frequency 50 Hz is applied to a series LCR circuit in which R = 3 Ω, L = 25.48 mH, and C = 796 μF. Find the impedance of the circuit.
Year 2021
A light bulb of resistance 484 Ω is connected with 220 V ac supply. Find peak value of current through the bulb.
Prove that when an alternating voltage is applied to an inductor, the current through it lags behind voltage by an angle π/2.
(a) Working principle of transformer is
(i) mutual induction (ii) motional emf (iii) resonance (iv) LC oscillations.
(b) Write any one difference between step-up and step-down transformer.
(c) A power transmission line feeds input power at 3300 V to a step-down transformer with its primary windings having 6000 turns. What should be the number of turns in the secondary in order to get output power at 220 V?
Year 2022
In purely inductive or capacitive circuit, power factor (cos φ) is _____.
(i) State the principle of working of a transformer.
(ii) Explain briefly any three energy losses in a transformer.
Year 2023
Obtain the expression for the current flowing through a resistor when an a.c. voltage is applied to it.
(a) State the principle of a transformer.
(b) Explain the working of a transformer.
(c) Differentiate between step up transformer and step down transformer.
Year 2024
The household line voltage of ac measured is 220 V, calculate its peak voltage.
(a) Write the expression for instantaneous emf of a.c.
(b) Identify A, B and C in figure.
(c) Draw the phasor diagram of the above circuit and write the expression for impedance.
Year 2025
The instantaneous current and voltage of an a.c. circuit are given by
i = 10 sin 314t Ampere and v = 50 sin (314t + π/2) Volt.
(a) What is the phase difference between voltage and current?
(b) Power dissipation in the circuit?
(a) With the help of a phasor diagram, find the impedance of a series LCR circuit.
(b) A series LCR circuit is connected to an ac source of variable frequency. At what frequency will impedance be minimum?
Chapter 8: Electromagnetic Waves
Year 2020
A typical plane electromagnetic wave propagating along the Z direction is shown in figure.
(a) Write the equation for electric and magnetic fields.
(b) Write the methods of production of radio waves and microwaves. Write any one use of these waves.
Year 2021
The electromagnetic waves used in LASIK eye surgery is
(i) microwaves (ii) ultraviolet rays (iii) infra-red waves (iv) gamma rays.
(a) The current due to time varying electric field is called _______.
(b) An electromagnetic wave travels in free space with a velocity of 3 × 10⁸ m/s. At a particular point in space and time, magnitude of intensity of electric field is 6.3 V/m. What is magnitude of magnetic field at this point?
Year 2022
Relation between velocity of light (c), permeability of free space (μ₀), permittivity of free space (ε₀) is _____.
Infra-red waves are also referred to as heat waves. Why?
Year 2023
An accelerating charge produces _______ waves.
X-rays were discovered by _______ in 1895.
How Maxwell modified Ampere’s law?
Year 2024
Briefly explain the electromagnetic spectrum.
Year 2025
The frequencies of gamma-rays, ultraviolet rays, and X-rays are v₁, v₂ and v₃ respectively. Then
(i) v₁ = v₂ = v₃
(ii) v₁ > v₃ > v₂
(iii) v₁ > v₂ > v₃
(iv) v₃ > v₂ > v₁.
(a) Which electromagnetic wave is used in cellular phones to transmit voice communication?
(b) In the process of charging of a parallel plate capacitor, the current produced between the plates of the capacitor is ______.
Chapter 9: Ray Optics and Optical Instruments
Year 2020
Total internal reflection may be observed if
(a) light ray is travelling from denser medium to rarer medium
(b) light ray is travelling from rarer medium to denser medium
(c) light ray is travelling from any medium to another medium.
Optical fibres make use of the phenomenon of
(a) refraction (b) total internal reflection (c) interference (d) diffraction.
A magician during a show makes a glass lens with n = 1.47 disappear in a trough of liquid.
(a) What is the refractive index of the liquid?
(b) Could the liquid be water?
Explain why the bluish colour predominates in a clear sky.
The figure shows the image formation of an object in simple microscope.
(a) Find out the object distance and image distance from the figure.
(b) Derive an equation for magnifying power of the simple microscope.
Year 2021
Write Lens maker’s formula.
Using a suitable ray diagram prove that the radius of curvature of a spherical mirror is twice its focal length.
Using a suitable ray diagram derive the relation
n₂/v − n₁/u = (n₂ − n₁)/R for refraction at a spherical surface.
Draw a ray diagram showing the image formation in a refracting telescope when the final image is formed at infinity. Write an equation for the length of the telescope tube.
Draw a diagram showing a ray of light passing through a triangular glass prism. Derive an expression for the refractive index of the material of the prism.
Year 2022
Optical fibres make use the phenomenon of _____.
(i) If f = 0.5 m, for a glass lens, what is the power of the lens?
(ii) The radii of curvature of the faces of a double convex lens are 10 cm and 15 cm. Its focal length is 12 cm. What is the refractive index of glass?
(i) State Laws of refraction.
(ii) Obtain a relation for the total deviation produced for a ray incident on a prism.
Year 2023
What is total internal reflection?
Derive the expression for the refractive index of a prism.
(a) With a neat diagram, derive lens makers formula.
(b) The radii of curvature of the faces of a double convex lens are 10 cm and 15 cm. Its focal length is 12 cm. What is the refractive index of glass?
Year 2024
The SI unit of power of lens.
(a) State Snell’s law of refraction.
(b) Explain critical angle and total internal reflection.
(a) Derive lens maker’s formula.
(b) Draw the image formation in a simple microscope.
(c) Write the value of least distance of distinct vision.
Year 2025
Two thin lenses of power +4 D and −2 D are in contact. The focal length of the combination is _____.
(a) Draw a ray diagram of simple microscope showing image formation at the least distance of distinct vision (D).
(b) The magnification of a compound microscope is 20. The focal length of the eyepiece is 5 cm and the image is formed at the near point (25 cm). Find the magnification of objective lens.
(a) Draw the path of a light ray through the prism which suffers minimum deviation. Mark the angle of deviation, angle of incidence and angle of emergence.
(b) Using the above diagram, show that sum of the angle of deviation and the angle of the prism is equal to the sum of the angle of incidence and angle of emergence.
(c) What do you mean by angle of minimum deviation?
Chapter 10: Wave Optics
Year 2020
A long narrow slit is illuminated by blue light and the diffraction pattern is obtained on a white screen.
(a) How the width of bands change as the distance from the centre increases?
(b) What happens to the width of pattern, if yellow light is used instead of blue light?
(c) In a double slit experiment, the slits are separated by 0.03 cm and the screen is placed 1.5 m away. The distance between the central fringe and the fourth bright fringe is 1 cm. Determine the wavelength of light used.
(d) What do you mean by limit of resolution of an optical instrument?
Year 2021
Name the property of light that proves its transverse nature.
Using Huygens wave theory prove that angle of incidence is equal to angle of reflection.
Using Huygens wave theory derive Snell’s law.
Year 2022
Light waves are _____ in nature (transverse, longitudinal).
State Malus' law.
Using Huygens principle, explain refraction of a plane wave.
Year 2023
When the speed of light is independent of direction, the secondary waves are ________.
(a) State Huygens principle.
(b) Explain the refraction of plane wave using Huygens principle.
Year 2024
“The locus of points which have the same phase is called a wave front.” True/False.
(a) What are coherent sources?
(b) In Young’s double slit experiment, interference pattern is observed at 5 cm from the slits with a fringe width of 1 mm. Calculate the separation between the slits (λ = 5000 Å).
Year 2025
(a) Define wavefront.
(b) Figure shows a plane wavefront incident on a convex lens, draw the corresponding refracted wavefront.
Using Huygens concept of wavefront, derive Snell’s law of refraction.
Chapter 11: Dual Nature of Radiation and Matter
Year 2020
The work function of caesium metal is 2.14 eV. When light of frequency 6 × 10¹⁴ Hz is incident, photoemission occurs.
(a) Define work function.
(b) Calculate the maximum kinetic energy.
(c) Calculate the stopping potential.
Year 2021
Write the equation for the wavelength of de Broglie wave associated with a moving particle.
(a) Write Einstein’s photoelectric equation.
(b) Show that photoelectric emission is not possible if frequency is less than threshold frequency.
Year 2022
Photons are electrically _____.
(i) What is meant by threshold frequency?
(ii) Draw graph showing stopping potential vs frequency.
Year 2023
Explain work function.
Year 2024
Expression for de Broglie wavelength associated with a particle is _____.
What is stopping potential?
Year 2025
(a) Choose correct graph between KEmax and frequency.
(b) A photosensitive surface has work function 2.00 eV. Find KE of electrons for wavelength 300 nm.
Chapter 12: Atoms
Year 2020
The size of the atom in Thomson's model is _____ the atomic size in Rutherford's model.
The atomic line spectra of hydrogen atom is shown. Write the names of the series A, B and C.
Year 2021
Energy of electron in nth orbit of hydrogen atom is En = −13.6/n² eV.
What energy is required to free electron from first orbit?
If radius of first orbit is a₀, radius of second orbit is _______.
Write any two postulates of Bohr model.
Year 2022
The minimum energy required to free an electron from the ground state of hydrogen atom is _____.
(i) Draw energy level diagram and mark Balmer series.
(ii) Name spectral series in ultraviolet region.
Year 2023
Explain Rutherford’s alpha particle scattering experiment.
Year 2024
Write the postulates of Bohr’s atom model.
Year 2025
If radius of first orbit is r₀, radius of second orbit is _____.
What is meant by ionisation energy? Write its value for hydrogen atom.
Chapter 13: Nuclei
March 2020
Match the following:
A | B
(i) Nuclear fission | β-decay
(ii) Nuclear fusion | Hydrogen spectrum
(iii) Transition between atomic energy levels | Nuclei with low atomic numbers
(iv) Electron emission from nucleus | Generally possible for nuclei with high atomic number
| Photoelectric emission
Spontaneous and continuous disintegration of a nucleus of a heavy element with the emission of certain types of radiation is known as radioactivity.
(a) The radioactive isotope D decays according to the sequence
D → β⁻ → D₁ → α → D₂.
If the mass number and atomic number of D₂ are 172 and 71 respectively, what are the
(i) Mass number
(ii) Atomic number of D.
(b) State radioactive decay law.
(c) Write the relation connecting half-life and mean life of radioactive element.
March 2021
Write any two properties of nuclear force.
Define half-life of a radioactive sample. Write the equation that connects half-life with disintegration constant.
March 2022
Complete the general equation of α-decay.
AₓZ → _____ + ⁴₂He
(a) Y(A−4, Z−2)
(b) Y(A−2, Z−4)
(c) Y(A−2, Z−2)
(d) Y(A, Z+1)
Nuclear reactor is a device used to initiate and control a nuclear chain reaction. Explain the major parts of a nuclear reactor.
March 2023
Atoms of same element differing in mass are called _______.
(a) Isotones
(b) Isobars
(c) Isotopes
(d) Isomers
Differentiate between nuclear fission and nuclear fusion.
March 2024
Which element in the periodic table shows maximum binding energy per nucleon?
What is nuclear fission? Give one example.
March 2025
_______ process is responsible for the production of energy in sun.
(Nuclear fission / Nuclear fusion)
The carbon isotope ⁶C¹² has a nuclear mass of 12.000000 u.
Calculate the binding energy of its nucleus.
Given:
mₚ = 1.007825 u
mₙ = 1.008665 u
1 a.m.u. (u) = 931 MeV
Chapter 14: Semiconductor Electronics – Materials, Devices and Simple Circuits
March 2020
Diodes are one of the building elements of electronic circuits. Some type of diodes are shown in the figure.
(i) (ii) (iii)
(a) Identify rectifier diode from the figure.
(b) Draw the circuit diagram of a forward biased rectifier diode by using a battery.
The transfer characteristic of n-p-n transistor in CE configuration is shown in the figure.
(a) Find the cut off region, active region and saturation region from it.
(b) In which of these regions, a transistor is said to be switched off.
(c) A CE transistor amplifier is shown in figure. In this, the audio signal voltage across collector resistance of 2.0 kΩ is 2.0 V. Suppose the current amplification factor of the transistor is 100. Then calculate the value of signal current through the base.
(d) In the working of a transistor, the emitter-base (EB) junction is forward biased while collector-base (CB) junction is reverse biased. Why?
March 2021
The symbol of a logic gate is given below. Identify the gate and write its truth table.
(a) In which figure the diode is under forward biased condition?
(b) Draw the circuit diagram of a full wave rectifier and explain its working.
March 2022
Draw the input and output waveform of a half-wave rectifier.
(i) Identify the logic gate.
(ii) Write down the truth table of this gate.
(iii) Why this gate is also called universal gate?
March 2023
(a) Give the classification of materials based on energy band diagram.
(b) Differentiate between intrinsic and extrinsic semiconductors.
March 2024
What is an intrinsic semiconductor?
What is a rectifier? Draw the circuit diagram and input, output waveforms of a full wave rectifier.
March 2025
With the help of a circuit diagram, explain the working of a half wave rectifier. Draw the input and output waveforms.
