The Bihar Board Class 12th Physics Exam 2026 is one of the most important examinations for students preparing for their final board exams. Physics objective questions carry a high weightage and help students boost their marks quickly.
In this post, we are providing Bihar Board Class 12th Physics Objective Question 75 with Options and Answer to help you revise key concepts and practice effectively.
All questions are based on the latest syllabus prescribed by the Bihar School Examination Board (BSEB) and are ideal for quick last-minute revision.
Bihar Board Class 12th Physics Objective Question 75 with Options and Answer
Question 1 – The unit of electric charge is
(a) Ampere
(b) Volt
(c) Coulomb
(d) Ohm
Answer: (c) Coulomb
Question 2 – Electric field lines originate from
(a) Negative charge
(b) Positive charge
(c) Neutral body
(d) Magnetic field
Answer: (b) Positive charge
Question 3 – Coulomb’s law gives the force between
(a) Two magnetic poles
(b) Two stationary charges
(c) A charge and a current
(d) None of these
Answer: (b) Two stationary charges
Question 4 – The S.I. unit of potential difference is
(a) Joule
(b) Ohm
(c) Volt
(d) Coulomb
Answer: (c) Volt
Question 5 – The dielectric constant of a perfect vacuum is
(a) 1
(b) 0
(c) 2
(d) Infinity
Answer: (a) 1
Question 6 – The work done in moving a charge around a closed path in an electric field is
(a) Positive
(b) Negative
(c) Zero
(d) Infinite
Answer: (c) Zero
Question 7 – The unit of capacitance is
(a) Volt
(b) Farad
(c) Coulomb
(d) Ohm
Answer: (b) Farad
Question 8 – Ohm’s law is valid only when
(a) Temperature remains constant
(b) Resistance varies
(c) Voltage is constant
(d) None of these
Answer: (a) Temperature remains constant
Question 9 – The unit of resistance is
(a) Joule
(b) Ohm
(c) Volt
(d) Coulomb
Answer: (b) Ohm
Question 10 – The resistance of a wire depends upon
(a) Length
(b) Area of cross-section
(c) Nature of material
(d) All of these
Answer: (d) All of these
Question 11 – The resistivity of a conductor depends on
(a) Material of conductor
(b) Temperature
(c) Length
(d) Both a and b
Answer: (d) Both a and b
Question 12 – The unit of resistivity is
(a) Ohm-meter
(b) Ohm-centimeter
(c) Volt/meter
(d) None
Answer: (a) Ohm-meter
Question 13 – Which device measures current?
(a) Voltmeter
(b) Ammeter
(c) Wattmeter
(d) Ohmmeter
Answer: (b) Ammeter
Question 14 – A voltmeter is always connected in
(a) Series
(b) Parallel
(c) Both
(d) None
Answer: (b) Parallel
Question 15 – The power dissipated in a resistor is
(a) VI
(b) I²R
(c) V²/R
(d) All of these
Answer: (d) All of these
Question 16 – Magnetic field is produced by
(a) Static charge
(b) Moving charge
(c) Stationary magnet
(d) None
Answer: (b) Moving charge
Question 17 – The unit of magnetic flux is
(a) Tesla
(b) Weber
(c) Gauss
(d) Henry
Answer: (b) Weber
Question 18 – The unit of magnetic field intensity is
(a) Tesla
(b) Weber
(c) Joule
(d) Ampere
Answer: (a) Tesla
Question 19 – The direction of magnetic field lines inside a bar magnet is
(a) North to south
(b) South to north
(c) Circular
(d) Random
Answer: (b) South to north
Question 20 – The magnetic field at the center of a circular coil is directly proportional to
(a) Radius
(b) Current
(c) Area
(d) None
Answer: (b) Current
Question 21 – The right-hand thumb rule is used to find
(a) Direction of electric current
(b) Direction of magnetic field
(c) Magnitude of charge
(d) Power
Answer: (b) Direction of magnetic field
Question 22 – The magnetic flux linked with a coil depends on
(a) Number of turns
(b) Magnetic field strength
(c) Area of coil
(d) All of these
Answer: (d) All of these
Question 23 – Faraday’s law of electromagnetic induction gives
(a) Induced current
(b) Induced emf
(c) Magnetic field
(d) None
Answer: (b) Induced emf
Question 24 – Lenz’s law is based on
(a) Conservation of energy
(b) Conservation of momentum
(c) Conservation of charge
(d) None
Answer: (a) Conservation of energy
Question 25 – Transformer works on
(a) Mutual induction
(b) Self-induction
(c) Conduction
(d) None
Answer: (a) Mutual induction
Question 26 – The core of a transformer is made of
(a) Copper
(b) Soft iron
(c) Aluminium
(d) Steel
Answer: (b) Soft iron
Question 27 – An electric motor converts
(a) Electrical energy into mechanical energy
(b) Mechanical energy into electrical energy
(c) Heat energy into light
(d) None
Answer: (a) Electrical energy into mechanical energy
Question 28 – The SI unit of inductance is
(a) Henry
(b) Tesla
(c) Joule
(d) Weber
Answer: (a) Henry
Question 29 – Electromagnetic waves are
(a) Longitudinal
(b) Transverse
(c) Mechanical
(d) None
Answer: (b) Transverse
Question 30 – The speed of light in vacuum is
(a) 3 × 10⁸ m/s
(b) 3 × 10⁵ m/s
(c) 3 × 10⁶ m/s
(d) 3 × 10⁴ m/s
Answer: (a) 3 × 10⁸ m/s
Question 31 – The property of light used in a plane mirror is
(a) Reflection
(b) Refraction
(c) Diffraction
(d) Interference
Answer: (a) Reflection
Question 32 – The image formed by a plane mirror is
(a) Real and inverted
(b) Virtual and erect
(c) Real and erect
(d) None
Answer: (b) Virtual and erect
Question 33 – The focal length of a plane mirror is
(a) Infinite
(b) Zero
(c) One
(d) None
Answer: (a) Infinite
Question 34 – The refractive index of vacuum is
(a) 1
(b) 0
(c) 2
(d) Infinity
Answer: (a) 1
Question 35 – A convex lens is also called
(a) Converging lens
(b) Diverging lens
(c) Plane lens
(d) Cylindrical lens
Answer: (a) Converging lens
Question 36 – A concave lens is also known as
(a) Diverging lens
(b) Converging lens
(c) Plane lens
(d) None
Answer: (a) Diverging lens
Question 37 – The power of a lens is measured in
(a) Diopter
(b) Meter
(c) Watt
(d) Volt
Answer: (a) Diopter
Question 38 – The rainbow formation is due to
(a) Dispersion of light
(b) Reflection
(c) Refraction
(d) Absorption
Answer: (a) Dispersion of light
Question 39 – The unit of frequency is
(a) Hertz
(b) Second
(c) Joule
(d) Watt
Answer: (a) Hertz
Question 40 – The color of light having the highest wavelength is
(a) Red
(b) Violet
(c) Blue
(d) Green
Answer: (a) Red
Question 41 – The color of light having the shortest wavelength is
(a) Violet
(b) Yellow
(c) Blue
(d) Green
Answer: (a) Violet
Question 42 – The speed of light is maximum in
(a) Vacuum
(b) Air
(c) Glass
(d) Water
Answer: (a) Vacuum
Question 43 – The dual nature of radiation is explained by
(a) Einstein
(b) Newton
(c) Planck
(d) Bohr
Answer: (a) Einstein
Question 44 – The energy of a photon is given by
(a) E = hf
(b) E = mc²
(c) E = ½mv²
(d) E = h/λ
Answer: (a) E = hf
Question 45 – The unit of Planck’s constant is
(a) Joule-second
(b) Joule/meter
(c) Joule/coulomb
(d) None
Answer: (a) Joule-second
Question 46 – The rest mass of photon is
(a) Zero
(b) One
(c) Infinite
(d) Constant
Answer: (a) Zero
Question 47 – The electron was discovered by
(a) J.J. Thomson
(b) Rutherford
(c) Chadwick
(d) Bohr
Answer: (a) J.J. Thomson
Question 48 – Proton was discovered by
(a) Goldstein
(b) Bohr
(c) Thomson
(d) Chadwick
Answer: (a) Goldstein
Question 49 – Neutron was discovered by
(a) Chadwick
(b) Rutherford
(c) Thomson
(d) Bohr
Answer: (a) Chadwick
Question 50 – The nucleus was discovered by
(a) Rutherford
(b) Bohr
(c) Thomson
(d) Einstein
Answer: (a) Rutherford
Question 51 – The charge of an electron is
(a) –1.6 × 10⁻¹⁹ C
(b) +1.6 × 10⁻¹⁹ C
(c) Zero
(d) None
Answer: (a) –1.6 × 10⁻¹⁹ C
Question 52 – The mass of an electron is
(a) 9.1 × 10⁻³¹ kg
(b) 1.67 × 10⁻²⁷ kg
(c) 1.67 × 10⁻²⁴ kg
(d) 10⁻³⁰ kg
Answer: (a) 9.1 × 10⁻³¹ kg
Question 53 – Bohr’s model explains
(a) Hydrogen atom
(b) Helium atom
(c) Neon atom
(d) Lithium atom
Answer: (a) Hydrogen atom
Question 54 – The smallest particle of an element is
(a) Atom
(b) Molecule
(c) Ion
(d) Nucleus
Answer: (a) Atom
Question 55 – Alpha particle consists of
(a) 2 protons and 2 neutrons
(b) 2 protons only
(c) 2 electrons
(d) 1 proton and 1 neutron
Answer: (a) 2 protons and 2 neutrons
Question 56 – Beta particles are
(a) Electrons
(b) Protons
(c) Neutrons
(d) Positrons
Answer: (a) Electrons
Question 57 – Gamma rays are
(a) Electromagnetic waves
(b) Charged particles
(c) Alpha particles
(d) None
Answer: (a) Electromagnetic waves
Question 58 – Nuclear fission was discovered by
(a) Hahn and Strassmann
(b) Curie
(c) Rutherford
(d) Bohr
Answer: (a) Hahn and Strassmann
Question 59 – The energy released in a nuclear reaction is due to
(a) Mass defect
(b) Heat
(c) Current
(d) None
Answer: (a) Mass defect
Question 60 – Nuclear reactor works on
(a) Controlled chain reaction
(b) Uncontrolled reaction
(c) Fusion
(d) Explosion
Answer: (a) Controlled chain reaction
Question 61 – Semiconductors are materials whose conductivity is
(a) Between conductors and insulators
(b) Greater than conductors
(c) Zero
(d) None
Answer: (a) Between conductors and insulators
Question 62 – Germanium and silicon are examples of
(a) Semiconductors
(b) Conductors
(c) Insulators
(d) Superconductors
Answer: (a) Semiconductors
Question 63 – A PN junction diode conducts in
(a) Forward bias
(b) Reverse bias
(c) Both
(d) None
Answer: (a) Forward bias
Question 64 – The device used to convert AC to DC is
(a) Rectifier
(b) Transformer
(c) Capacitor
(d) Inductor
Answer: (a) Rectifier
Question 65 – The transistor is made up of
(a) Two PN junctions
(b) One PN junction
(c) Three PN junctions
(d) None
Answer: (a) Two PN junctions
Question 66 – The logic gate with output 1 when both inputs are 0 is
(a) NOR
(b) AND
(c) OR
(d) NAND
Answer: (a) NOR
Question 67 – The instrument used to detect current is
(a) Galvanometer
(b) Ammeter
(c) Voltmeter
(d) None
Answer: (a) Galvanometer
Question 68 – Communication system works on
(a) Modulation and demodulation
(b) Reflection
(c) Refraction
(d) Transmission
Answer: (a) Modulation and demodulation
Question 69 – AM stands for
(a) Amplitude Modulation
(b) Angular Motion
(c) Atomic Mass
(d) Average Mode
Answer: (a) Amplitude Modulation
Question 70 – FM stands for
(a) Frequency Modulation
(b) Force Motion
(c) Field Measurement
(d) Fast Mode
Answer: (a) Frequency Modulation
Question 71 – The speed of electromagnetic waves in vacuum is
(a) Equal to speed of light
(b) Greater than light
(c) Less than sound
(d) None
Answer: (a) Equal to speed of light
Question 72 – Which type of wave requires no medium for propagation?
(a) Electromagnetic wave
(b) Sound wave
(c) Mechanical wave
(d) Water wave
Answer: (a) Electromagnetic wave
Question 73 – The SI unit of power is
(a) Watt
(b) Joule
(c) Volt
(d) Ampere
Answer: (a) Watt
Question 74 – The frequency of AC used in India is
(a) 50 Hz
(b) 60 Hz
(c) 40 Hz
(d) 70 Hz
Answer: (a) 50 Hz
Question 75 – The instrument used to measure potential difference is
(a) Voltmeter
(b) Ammeter
(c) Galvanometer
(d) Multimeter
Answer: (a) Voltmeter
10 Most Important FAQs-Bihar Board Class 12th Physics Objective Question
1. How many objective questions come in Bihar Board Class 12th Physics exam?
Usually, 35 objective-type questions are asked carrying one mark each.
2. Are these questions based on the latest Bihar Board syllabus?
Yes, all questions are based on the updated BSEB Class 12 Physics syllabus 2026.
3. Which chapters are most important for Physics MCQs?
Electrostatics, Current Electricity, Magnetism, Optics, and Semiconductor Electronics are crucial.
4. Are numerical questions included in the objective section?
Yes, a few objective questions are numerical-based in the Physics exam.
5. How to prepare objective questions effectively?
Revise NCERT concepts, memorize formulas, and solve previous-year objective sets.
6. What is the passing mark for Bihar Board Class 12 Physics?
Students need at least 33% marks in both theory and practical to pass.
7. What is the total mark of the Physics paper?
Physics paper carries 70 marks for theory and 30 marks for practical.
8. Is calculator allowed in the Physics exam?
No, electronic calculators are not allowed in the board examination.
9. When will the Bihar Board Class 12 exam be conducted in 2026?
The exam is expected to be held in February–March 2026.
10. How to download Bihar Board Class 12 Physics model paper?
You can download it from the official website:
Conclusion-Bihar Board Class 12th Physics Objective Question
We hope this collection of Bihar Board Class 12th Physics Objective Question 75 with Options and Answer helps you in scoring high marks in your upcoming examination. Practice daily, revise concepts, and go through past year papers for the best results.
We are completed Bihar Board Class 12th Physics Objective Question