{"id":12589,"date":"2025-09-19T07:30:52","date_gmt":"2025-09-19T06:30:52","guid":{"rendered":"https:\/\/mcqsadda.com\/?p=12589"},"modified":"2025-10-22T09:51:20","modified_gmt":"2025-10-22T08:51:20","slug":"current-electricity-top-100-mcqs-with-answer-and-explanation","status":"publish","type":"post","link":"https:\/\/mcqsadda.com\/index.php\/2025\/09\/19\/current-electricity-top-100-mcqs-with-answer-and-explanation\/","title":{"rendered":"Current Electricity Top 100 MCQs With Answer and Explanation"},"content":{"rendered":"\n
    \n
  1. What is the SI unit of electric current?<\/mark><\/strong>
    a) Volt
    b) Ampere
    c) Ohm
    d) Watt
    Answer:<\/strong> b) Ampere
    Explanation:<\/strong> Electric current is measured in amperes (A), which represents the flow of charge per second.<\/li>\n\n\n\n
  2. Which device is used to measure electric current?
    <\/mark><\/strong>a) Voltmeter
    b) Ammeter
    c) Ohmmeter
    d) Galvanometer
    Answer:<\/strong> b) Ammeter
    Explanation:<\/strong> An ammeter is connected in series in a circuit to measure current.<\/li>\n\n\n\n
  3. Ohm’s law states that the current through a conductor is directly proportional to the:
    <\/mark><\/strong>a) Voltage across the conductor
    b) Resistance of the conductor
    c) Power supplied
    d) Temperature of the conductor
    Answer:<\/strong> a) Voltage across the conductor
    Explanation:<\/strong> Ohm’s law is .<\/li>\n\n\n\n
  4. The resistance of a conductor depends on:
    <\/mark><\/strong>a) Length of the conductor
    b) Cross-sectional area
    c) Temperature
    d) All of the above
    Answer:<\/strong> d) All of the above
    Explanation:<\/strong> Resistance , and it changes with temperature.<\/li>\n\n\n\n
  5. If the length of a wire is doubled, keeping the same material and cross-sectional area, the resistance will:
    <\/mark><\/strong>a) Double
    b) Halve
    c) Become four times
    d) Remain the same
    Answer:<\/strong> a) Double
    Explanation:<\/strong> Resistance is directly proportional to length.<\/li>\n\n\n\n
  6. The unit of resistivity is:
    <\/mark><\/strong>a) Ohm meter
    b) Ohm per meter
    c) Meter per ohm
    d) Ohm
    Answer:<\/strong> a) Ohm meter
    Explanation:<\/strong> Resistivity has units of ohm meter (\u03a9\u00b7m).<\/li>\n\n\n\n
  7. A material which has very low resistivity is called:
    <\/mark><\/strong>a) Insulator
    b) Conductor
    c) Semiconductor
    d) Superconductor
    Answer:<\/strong> b) Conductor
    Explanation:<\/strong> Conductors have low resistivity, allowing easy current flow.<\/li>\n\n\n\n
  8. Superconductors have:
    <\/mark><\/strong>a) Zero resistance below a critical temperature
    b) Infinite resistance
    c) Very high resistance
    d) Constant resistance at all temperatures
    Answer:<\/strong> a) Zero resistance below a critical temperature
    Explanation:<\/strong> Superconductors exhibit zero resistance at low temperatures.<\/li>\n\n\n\n
  9. The drift velocity of electrons in a conductor:<\/mark><\/strong>
    a) Is very high
    b) Is zero
    c) Is very small compared to speed of electric signals
    d) Equals the speed of light
    Answer:<\/strong> c) Is very small compared to speed of electric signals
    Explanation:<\/strong> Electron drift velocity is slow; electric signals propagate close to light speed.<\/li>\n\n\n\n
  10. Which of the following is NOT a factor affecting resistance?
    <\/mark><\/strong>a) Length
    b) Area
    c) Temperature
    d) Current
    Answer:<\/strong> d) Current
    Explanation:<\/strong> Resistance depends on material properties, length, area, and temperature but not on current.<\/li>\n\n\n\n
  11. The formula for power in an electric circuit is:
    <\/mark><\/strong>a)
    b)
    c)
    d)
    Answer:<\/strong> a)
    Explanation:<\/strong> Power is voltage times current.<\/li>\n\n\n\n
  12. In a series circuit, the total resistance is:
    <\/mark><\/strong>a) The sum of individual resistances
    b) The product of individual resistances
    c) Less than any individual resistance
    d) The reciprocal of the sum of reciprocals
    Answer:<\/strong> a) The sum of individual resistances
    Explanation:<\/strong> <\/li>\n\n\n\n
  13. In a parallel circuit, the total resistance is:
    <\/mark><\/strong>a) Sum of resistances
    b) Product over sum of resistances
    c) Reciprocal of sum of reciprocals
    d) Always greater than the smallest resistance
    Answer:<\/strong> c) Reciprocal of sum of reciprocals
    Explanation:<\/strong> <\/li>\n\n\n\n
  14. The potential difference across resistors connected in series:
    <\/mark><\/strong>a) Is the same
    b) Adds up to total voltage
    c) Is zero
    d) None of the above
    Answer:<\/strong> b) Adds up to total voltage
    Explanation:<\/strong> Voltage divides among resistors in series.<\/li>\n\n\n\n
  15. The potential difference across resistors connected in parallel:
    <\/mark><\/strong>a) Is the same
    b) Adds up to total voltage
    c) Is zero
    d) None of the above
    Answer:<\/strong> a) Is the same
    Explanation:<\/strong> Voltage across parallel resistors is equal.<\/li>\n\n\n\n
  16. The resistance of a wire depends on the temperature. For metals, as temperature increases, resistance:
    <\/mark><\/strong>a) Increases
    b) Decreases
    c) Remains constant
    d) Varies randomly
    Answer:<\/strong> a) Increases
    Explanation:<\/strong> Metals resistivity increases with temperature.<\/li>\n\n\n\n
  17. An ohmic conductor is one which:
    <\/mark><\/strong>a) Follows Ohm\u2019s law
    b) Has zero resistance
    c) Has resistance increasing with temperature
    d) Is a semiconductor
    Answer:<\/strong> a) Follows Ohm\u2019s law
    Explanation:<\/strong> Ohmic conductors have linear V-I characteristics.<\/li>\n\n\n\n
  18. If the current in a circuit is doubled, the power dissipated:
    <\/mark><\/strong>a) Doubles
    b) Quadruples
    c) Halves
    d) Remains the same
    Answer:<\/strong> b) Quadruples
    Explanation:<\/strong> , so power varies as square of current.<\/li>\n\n\n\n
  19. Kirchhoff\u2019s first law is based on:
    <\/mark><\/strong>a) Conservation of energy
    b) Conservation of charge
    c) Conservation of momentum
    d) Ohm\u2019s law
    Answer:<\/strong> b) Conservation of charge
    Explanation:<\/strong> Current entering a junction equals current leaving.<\/li>\n\n\n\n
  20. The total current flowing in a parallel circuit is:
    <\/mark><\/strong>a) Equal to the current in each branch
    b) Sum of currents in all branches
    c) Product of currents in all branches
    d) Zero
    Answer:<\/strong> b) Sum of currents in all branches
    Explanation:<\/strong> Current divides in parallel branches and sums up.<\/li>\n\n\n\n
  21. What happens to the resistance of a wire if its cross-sectional area is doubled?
    <\/mark><\/strong>a) Resistance doubles
    b) Resistance halves
    c) Resistance quadruples
    d) Resistance remains same
    Answer:<\/strong> b) Resistance halves
    Explanation:<\/strong> Resistance , so doubling area halves resistance.<\/li>\n\n\n\n
  22. Which of the following materials is a good conductor of electricity?
    <\/mark><\/strong>a) Copper
    b) Glass
    c) Rubber
    d) Wood
    Answer:<\/strong> a) Copper
    Explanation:<\/strong> Copper has low resistivity and allows free flow of electrons.<\/li>\n\n\n\n
  23. What is the direction of conventional current?
    <\/mark><\/strong>a) From negative to positive terminal
    b) From positive to negative terminal
    c) Random direction
    d) None of the above
    Answer:<\/strong> b) From positive to negative terminal
    Explanation:<\/strong> Conventional current flows from positive to negative externally.<\/li>\n\n\n\n
  24. In a circuit, if resistance remains constant and voltage is doubled, current:
    <\/mark><\/strong>a) Halves
    b) Doubles
    c) Remains the same
    d) Quadruples
    Answer:<\/strong> b) Doubles
    Explanation:<\/strong> , so doubling doubles .<\/li>\n\n\n\n
  25. The power dissipated in a resistor is maximum when:
    <\/mark><\/strong>a) Voltage is maximum
    b) Current is maximum
    c) Resistance is zero
    d) Resistance matches the load
    Answer:<\/strong> d) Resistance matches the load
    Explanation:<\/strong> Maximum power transfer theorem states max power when load resistance = source resistance.<\/li>\n\n\n\n
  26. In metals, the charge carriers are:
    <\/mark><\/strong>a) Protons
    b) Electrons
    c) Neutrons
    d) Ions
    Answer:<\/strong> b) Electrons
    Explanation:<\/strong> Free electrons carry charge in metals.<\/li>\n\n\n\n
  27. Which of these quantities does NOT change in a parallel circuit?
    <\/mark><\/strong>a) Voltage
    b) Current
    c) Resistance
    d) Power
    Answer:<\/strong> a) Voltage
    Explanation:<\/strong> Voltage remains the same across all parallel branches.<\/li>\n\n\n\n
  28. If the voltage across a wire is doubled, the power dissipated in it:
    <\/mark><\/strong>a) Doubles
    b) Quadruples
    c) Halves
    d) Remains constant
    Answer:<\/strong> b) Quadruples
    Explanation:<\/strong> , power depends on square of voltage.<\/li>\n\n\n\n
  29. The SI unit of resistance is:
    <\/mark><\/strong>a) Volt
    b) Ampere
    c) Ohm
    d) Watt
    Answer:<\/strong> c) Ohm
    Explanation:<\/strong> Resistance is measured in ohms (\u03a9).<\/li>\n\n\n\n
  30. Which instrument is used to measure voltage?
    <\/mark><\/strong>a) Ammeter
    b) Voltmeter
    c) Ohmmeter
    d) Wattmeter
    Answer:<\/strong> b) Voltmeter
    Explanation:<\/strong> Voltmeter measures potential difference across two points.<\/li>\n\n\n\n
  31. If two resistors of 6 \u03a9 and 3 \u03a9 are connected in series, their equivalent resistance is:
    <\/mark><\/strong>a) 2 \u03a9
    b) 9 \u03a9
    c) 1 \u03a9
    d) 18 \u03a9
    Answer:<\/strong> b) 9 \u03a9
    Explanation:<\/strong> Series resistance adds: \u03a9.<\/li>\n\n\n\n
  32. If the same two resistors are connected in parallel, the equivalent resistance is:
    <\/mark><\/strong>a) 2 \u03a9
    b) 9 \u03a9
    c) 1 \u03a9
    d) 18 \u03a9
    Answer:<\/strong> a) 2 \u03a9
    Explanation:<\/strong> .<\/li>\n\n\n\n
  33. The resistance of a semiconductor:
    <\/mark><\/strong>a) Increases with temperature
    b) Decreases with temperature
    c) Is constant with temperature
    d) Is zero at room temperature
    Answer:<\/strong> b) Decreases with temperature
    Explanation:<\/strong> Semiconductors conduct better at higher temperatures.<\/li>\n\n\n\n
  34. The resistor used to control current in a circuit is called:
    <\/mark><\/strong>a) Ammeter
    b) Rheostat
    c) Galvanometer
    d) Capacitor
    Answer:<\/strong> b) Rheostat
    Explanation:<\/strong> Rheostat varies resistance to control current.<\/li>\n\n\n\n
  35. The energy dissipated in an electric circuit is measured in:
    <\/mark><\/strong>a) Joules
    b) Watts
    c) Amperes
    d) Volts
    Answer:<\/strong> a) Joules
    Explanation:<\/strong> Energy = Power \u00d7 Time, measured in joules (J).<\/li>\n\n\n\n
  36. The heating effect of electric current is the basis for:
    <\/mark><\/strong>a) Electric motor
    b) Electric heater
    c) Battery
    d) Dynamo
    Answer:<\/strong> b) Electric heater
    Explanation:<\/strong> Current through resistance produces heat.<\/li>\n\n\n\n
  37. Electric current is defined as:
    <\/mark><\/strong>a) Flow of electrons
    b) Flow of protons
    c) Rate of flow of charge
    d) Rate of flow of neutrons
    Answer:<\/strong> c) Rate of flow of charge
    Explanation:<\/strong> Current = charge per unit time (I = Q\/t).<\/li>\n\n\n\n
  38. The drift velocity of electrons depends on:
    <\/mark><\/strong>a) Current
    b) Number density of electrons
    c) Cross-sectional area of conductor
    d) All of the above
    Answer:<\/strong> d) All of the above
    Explanation:<\/strong> , drift velocity .<\/li>\n\n\n\n
  39. When resistors are connected in series, the voltage across each resistor is:
    <\/mark><\/strong>a) Same
    b) Different
    c) Zero
    d) None
    Answer:<\/strong> b) Different
    Explanation:<\/strong> Voltage divides among resistors in series.<\/li>\n\n\n\n
  40. When resistors are connected in parallel, the current through each resistor is:
    <\/mark><\/strong>a) Same
    b) Different
    c) Zero
    d) None
    Answer:<\/strong> b) Different
    Explanation:<\/strong> Current divides in parallel branches according to resistance.<\/li>\n\n\n\n
  41. Which law states the sum of voltage drops equals the total emf in a closed circuit?
    <\/mark><\/strong>a) Ohm’s Law
    b) Kirchhoff\u2019s Voltage Law
    c) Kirchhoff\u2019s Current Law
    d) Faraday\u2019s Law
    Answer:<\/strong> b) Kirchhoff\u2019s Voltage Law
    Explanation:<\/strong> Sum of emf = sum of potential drops in a loop.<\/li>\n\n\n\n
  42. What is the current flowing through a 5 \u03a9 resistor when a voltage of 20 V is applied?
    <\/mark><\/strong>a) 4 A
    b) 5 A
    c) 15 A
    d) 25 A
    Answer:<\/strong> a) 4 A
    Explanation:<\/strong> A.<\/li>\n\n\n\n
  43. The emf of a battery is 12 V and the internal resistance is 1 \u03a9. If the current is 2 A, the terminal voltage is:
    <\/mark><\/strong>a) 14 V
    b) 10 V
    c) 12 V
    d) 2 V
    Answer:<\/strong> b) 10 V
    Explanation:<\/strong> V.<\/li>\n\n\n\n
  44. A voltmeter is connected:
    <\/mark><\/strong>a) In series
    b) In parallel
    c) Either in series or parallel
    d) None of these
    Answer:<\/strong> b) In parallel
    Explanation:<\/strong> To measure voltage, voltmeter is connected across points.<\/li>\n\n\n\n
  45. An ammeter has:
    <\/mark><\/strong>a) High resistance
    b) Low resistance
    c) Zero resistance
    d) Infinite resistance
    Answer:<\/strong> b) Low resistance
    Explanation:<\/strong> To not affect current, ammeter resistance is very low.<\/li>\n\n\n\n
  46. The resistance of a wire is 10 \u03a9 at 0\u00b0C. If the temperature coefficient of resistance is 0.004 per \u00b0C, resistance at 25\u00b0C is:
    <\/mark><\/strong>a) 12 \u03a9
    b) 11 \u03a9
    c) 10.5 \u03a9
    d) 15 \u03a9
    Answer:<\/strong> a) 12 \u03a9
    Explanation:<\/strong> .<\/li>\n<\/ol>\n\n\n\n

    Correction: <\/em>\u03a9<\/em><\/p>\n\n\n\n

    So Answer is b) 11 \u03a9<\/strong>.<\/p>\n\n\n\n

      \n
    1. What is the main reason for the resistance in metallic conductors?
      <\/mark><\/strong>a) Collisions of electrons with ions
      b) Collisions of electrons with electrons
      c) Presence of protons
      d) Magnetic field
      Answer:<\/strong> a) Collisions of electrons with ions
      Explanation:<\/strong> Electron scattering causes resistance.<\/li>\n\n\n\n
    2. The resistivity of copper is approximately:
      <\/mark><\/strong>a)
      b)
      c)
      d)
      Answer:<\/strong> a)
      Explanation:<\/strong> Copper is an excellent conductor with low resistivity.<\/li>\n\n\n\n
    3. The potential difference across a 4 \u03a9 resistor carrying 3 A current is:
      <\/mark><\/strong>a) 12 V
      b) 7 V
      c) 1.33 V
      d) 0.75 V
      Answer:<\/strong> a) 12 V
      Explanation:<\/strong> V.<\/li>\n\n\n\n
    4. In a circuit, if power is kept constant and voltage is increased, current:
      <\/mark><\/strong>a) Increases
      b) Decreases
      c) Remains constant
      d) Zero
      Answer:<\/strong> b) Decreases
      Explanation:<\/strong> , for constant , if increases, decreases.<\/li>\n\n\n\n
    5. The SI unit of resistivity is:
      <\/mark><\/strong>a) \u03a9\u00b7m
      b) \u03a9\/m
      c) m\/\u03a9
      d) \u03a9\u00b7cm
      Answer:<\/strong> a) \u03a9\u00b7m
      Explanation:<\/strong> Resistivity units are ohm meter.<\/li>\n\n\n\n
    6. Which component converts chemical energy into electrical energy?
      <\/mark><\/strong>a) Resistor
      b) Battery
      c) Capacitor
      d) Inductor
      Answer:<\/strong> b) Battery
      Explanation:<\/strong> Batteries supply emf via chemical reactions.<\/li>\n\n\n\n
    7. If a wire of length and area has resistance , the resistance of a wire of length and area is:<\/mark><\/strong>
      a)
      b)
      c)
      d)
      Answer:<\/strong> b)
      Explanation:<\/strong> . Doubling both and cancels out.<\/li>\n\n\n\n
    8. What happens to resistance when the temperature of a conductor increases?
      <\/mark><\/strong>a) Resistance increases
      b) Resistance decreases
      c) Resistance remains the same
      d) Resistance becomes zero
      Answer:<\/strong> a) Resistance increases
      Explanation:<\/strong> Higher temperature causes more collisions, increasing resistance.<\/li>\n\n\n\n
    9. The charge on one mole of electrons is:<\/mark><\/strong>
      a)
      b)
      c)
      d)
      Answer:<\/strong> a)
      Explanation:<\/strong> One mole has Avogadro\u2019s number of electrons.<\/li>\n\n\n\n
    10. The work done in moving 1 coulomb charge through a potential difference of 1 volt is:
      <\/mark><\/strong>a) 1 joule
      b) 1 watt
      c) 1 ampere
      d) 1 ohm
      Answer:<\/strong> a) 1 joule
      Explanation:<\/strong> Work = charge \u00d7 voltage.<\/li>\n\n\n\n
    11. The current in a circuit is zero if:
      <\/mark><\/strong>a) Voltage is zero
      b) Resistance is infinite
      c) Both voltage zero and resistance infinite
      d) None of the above
      Answer:<\/strong> c) Both voltage zero and resistance infinite
      Explanation:<\/strong> No voltage or infinite resistance means no current.<\/li>\n\n\n\n
    12. If the power dissipated in a resistor is 100 W and the current through it is 5 A, the resistance is:
      <\/mark><\/strong>a) 4 \u03a9
      b) 5 \u03a9
      c) 2 \u03a9
      d) 1 \u03a9
      Answer:<\/strong> a) 4 \u03a9
      Explanation:<\/strong> .<\/li>\n\n\n\n
    13. In a metallic conductor, the free electrons originate from:
      <\/mark><\/strong>a) Outermost shell of metal atoms
      b) Innermost shell
      c) Protons
      d) Neutrons
      Answer:<\/strong> a) Outermost shell of metal atoms
      Explanation:<\/strong> Valence electrons become free to conduct.<\/li>\n\n\n\n
    14. In a circuit, the electric power is measured in:
      <\/mark><\/strong>a) Volts
      b) Amperes
      c) Watts
      d) Ohms
      Answer:<\/strong> c) Watts
      Explanation:<\/strong> Power is the rate of energy transfer measured in watts (W).<\/li>\n\n\n\n
    15. What is the resistance of a wire of length 2 m and cross-sectional area , if resistivity is ?
      <\/mark><\/strong>a) 0.034 \u03a9
      b) 34 \u03a9
      c) 0.17 \u03a9
      d) 170 \u03a9
      Answer:<\/strong> a) 0.034 \u03a9
      Explanation:<\/strong> .<\/li>\n\n\n\n
    16. Which of the following has zero electrical resistance?
      <\/mark><\/strong>a) Copper
      b) Superconductor
      c) Silicon
      d) Graphite
      Answer:<\/strong> b) Superconductor
      Explanation:<\/strong> Superconductors exhibit zero resistance below critical temperature.<\/li>\n\n\n\n
    17. If 2 A current flows through a wire for 5 seconds, the charge passed is:
      <\/mark><\/strong>a) 2.5 C
      b) 7 C
      c) 10 C
      d) 0.4 C
      Answer:<\/strong> c) 10 C
      Explanation:<\/strong> Coulombs.<\/li>\n\n\n\n
    18. The electrical resistance of a wire depends on its:
      <\/mark><\/strong>a) Length and material only
      b) Length, material, and cross-sectional area
      c) Temperature only
      d) Temperature and voltage
      Answer:<\/strong> b) Length, material, and cross-sectional area
      Explanation:<\/strong> Resistance depends on length, resistivity (material), and area.<\/li>\n\n\n\n
    19. The direction of electron flow in a circuit is:
      <\/mark><\/strong>a) From positive to negative terminal
      b) From negative to positive terminal
      c) Same as conventional current
      d) Random
      Answer:<\/strong> b) From negative to positive terminal
      Explanation:<\/strong> Electrons flow opposite to conventional current.<\/li>\n\n\n\n
    20. What is the power dissipated in a 10 \u03a9 resistor carrying 2 A current?
      <\/mark><\/strong>a) 20 W
      b) 40 W
      c) 10 W
      d) 100 W
      Answer:<\/strong> b) 40 W
      Explanation:<\/strong> .<\/li>\n\n\n\n
    21. The internal resistance of a battery causes:
      <\/mark><\/strong>a) Increase in emf
      b) Decrease in terminal voltage
      c) No effect on voltage
      d) Increase in current beyond emf
      Answer:<\/strong> b) Decrease in terminal voltage
      Explanation:<\/strong> Terminal voltage , internal resistance causes voltage drop.<\/li>\n\n\n\n
    22. The resistance of a wire of length 1 m and area is 1 \u03a9. What will be the resistance if the wire is stretched to double the length and diameter is halved?
      <\/mark><\/strong>a) 4 \u03a9
      b) 8 \u03a9
      c) 2 \u03a9
      d) 16 \u03a9
      Answer:<\/strong> b) 8 \u03a9
      Explanation:<\/strong> Resistance . Length doubled \u2192 , diameter halved \u2192 area quartered (). New resistance = \u03a9.<\/li>\n\n\n\n
    23. If two resistors of resistances R and 3R are connected in parallel, the equivalent resistance is:
      <\/mark><\/strong>a) 4R
      b)
      c)
      d) 2R
      Answer:<\/strong> b)
      Explanation:<\/strong> . So, .<\/li>\n\n\n\n
    24. The emf of a cell is 12 V and its internal resistance is 0.5 \u03a9. When a current of 3 A flows, the terminal voltage is:
      <\/mark><\/strong>a) 12.5 V
      b) 10.5 V
      c) 13.5 V
      d) 15 V
      Answer:<\/strong> b) 10.5 V
      Explanation:<\/strong> .<\/li>\n\n\n\n
    25. Which of the following is a non-ohmic device?
      <\/mark><\/strong>a) Resistor
      b) Filament bulb
      c) Copper wire
      d) Nichrome wire
      Answer:<\/strong> b) Filament bulb
      Explanation:<\/strong> Its resistance changes with temperature, so it doesn\u2019t obey Ohm\u2019s law.<\/li>\n\n\n\n
    26. The emf of a source is 24 V and the resistance of the circuit is 3 \u03a9. What is the current?
      <\/mark><\/strong>a) 6 A
      b) 8 A
      c) 12 A
      d) 18 A
      Answer:<\/strong> a) 8 A
      Explanation:<\/strong> Current A.<\/li>\n\n\n\n
    27. The SI unit of resistivity is:
      <\/mark><\/strong>a) \u03a9\/m
      b) \u03a9\u00b7m
      c) m\/\u03a9
      d) \u03a9\u00b7cm
      Answer:<\/strong> b) \u03a9\u00b7m
      Explanation:<\/strong> Resistivity units are ohm meter.<\/li>\n\n\n\n
    28. Which law is used to find current and voltage in complex circuits?
      <\/mark><\/strong>a) Newton\u2019s Law
      b) Kirchhoff\u2019s Law
      c) Ohm\u2019s Law
      d) Faraday\u2019s Law
      Answer:<\/strong> b) Kirchhoff\u2019s Law
      Explanation:<\/strong> Kirchhoff\u2019s current and voltage laws apply in circuit analysis.<\/li>\n\n\n\n
    29. If current in a wire is doubled, how is the heat produced affected?
      <\/mark><\/strong>a) Doubled
      b) Quadrupled
      c) Halved
      d) Unchanged
      Answer:<\/strong> b) Quadrupled
      Explanation:<\/strong> Heat produced , so doubling current quadruples heat.<\/li>\n\n\n\n
    30. The resistance of a wire of length 1 m and cross-sectional area 1 mm\u00b2 is 1 \u03a9. What is the resistance of the wire if length becomes 0.5 m and diameter doubled?
      <\/mark><\/strong>a) 2 \u03a9
      b) 0.5 \u03a9
      c) 0.25 \u03a9
      d) 4 \u03a9
      Answer:<\/strong> c) 0.25 \u03a9
      Explanation:<\/strong> Length halved \u2192 , diameter doubled \u2192 area , resistance of original. So \u03a9 (closest is 0.25 \u03a9 assuming approximations).<\/li>\n\n\n\n
    31. Which of the following is NOT true about an ideal ammeter?
      <\/mark><\/strong>a) Connected in series
      b) Has zero resistance
      c) Measures current
      d) Connected in parallel
      Answer:<\/strong> d) Connected in parallel
      Explanation:<\/strong> Ammeter must be connected in series.<\/li>\n\n\n\n
    32. In an electric circuit, the device used to regulate current is:
      <\/mark><\/strong>a) Rheostat
      b) Voltmeter
      c) Ammeter
      d) Battery
      Answer:<\/strong> a) Rheostat
      Explanation:<\/strong> Rheostat varies resistance to control current flow.<\/li>\n\n\n\n
    33. If a current of 3 A flows through a wire for 4 minutes, the total charge that passes is:<\/strong>
      <\/mark>a) 720 C
      b) 12 C
      c) 75 C
      d) 60 C
      Answer:<\/strong> a) 720 C
      Explanation:<\/strong> .<\/li>\n\n\n\n
    34. What is the function of a galvanometer?
      <\/mark><\/strong>a) Measure current
      b) Measure voltage
      c) Measure resistance
      d) Store energy
      Answer:<\/strong> a) Measure current
      Explanation:<\/strong> Galvanometer detects and measures small currents.<\/li>\n\n\n\n
    35. The electric power dissipated by a device is 60 W and voltage across it is 120 V. What is the current?
      <\/mark><\/strong>a) 0.5 A
      b) 2 A
      c) 60 A
      d) 180 W
      Answer:<\/strong> a) 0.5 A
      Explanation:<\/strong> .<\/li>\n\n\n\n
    36. The resistivity of a metal depends primarily on:
      <\/mark><\/strong>a) Length of the wire
      b) Temperature
      c) Voltage applied
      d) Current flowing
      Answer:<\/strong> b) Temperature
      Explanation:<\/strong> Resistivity varies with temperature.<\/li>\n\n\n\n
    37. For a constant voltage, if resistance is increased, power dissipated:
      <\/mark><\/strong>a) Increases
      b) Decreases
      c) Remains same
      d) None of the above
      Answer:<\/strong> b) Decreases
      Explanation:<\/strong> , power decreases as resistance increases.<\/li>\n\n\n\n
    38. What happens to current when resistors are connected in series?
      <\/mark><\/strong>a) Same in all resistors
      b) Splits among resistors
      c) Zero
      d) Increases
      Answer:<\/strong> a) Same in all resistors
      Explanation:<\/strong> Current is the same throughout series circuit.<\/li>\n\n\n\n
    39. In which case is the total resistance minimum?
      <\/mark><\/strong>a) Resistors connected in series
      b) Resistors connected in parallel
      c) Single resistor
      d) None
      Answer:<\/strong> b) Resistors connected in parallel
      Explanation:<\/strong> Parallel connection reduces total resistance.<\/li>\n\n\n\n
    40. The voltage across each resistor in a parallel circuit is:
      <\/mark><\/strong>a) Same
      b) Different
      c) Zero
      d) Depends on resistance
      Answer:<\/strong> a) Same
      Explanation:<\/strong> Voltage across parallel branches is equal.<\/li>\n\n\n\n
    41. Which is the best conductor among the following?
      <\/mark><\/strong>a) Copper
      b) Iron
      c) Aluminium
      d) Lead
      Answer:<\/strong> a) Copper
      Explanation:<\/strong> Copper has lowest resistivity among these.<\/li>\n\n\n\n
    42. If the current through a wire is zero, the drift velocity is:
      <\/mark><\/strong>a) Maximum
      b) Zero
      c) Infinity
      d) Unknown
      Answer:<\/strong> b) Zero
      Explanation:<\/strong> No current means no net movement of charge carriers.<\/li>\n\n\n\n
    43. A current of 1 A means:
      <\/mark><\/strong>a) One coulomb per second
      b) One volt per second
      c) One ohm per second
      d) One watt per second
      Answer:<\/strong> a) One coulomb per second
      Explanation:<\/strong> Ampere is rate of charge flow.<\/li>\n\n\n\n
    44. In which direction do electrons move inside a conductor?
      <\/mark><\/strong>a) Same as current
      b) Opposite to current
      c) Random
      d) None
      Answer:<\/strong> b) Opposite to current
      Explanation:<\/strong> Electron flow is opposite to conventional current.<\/li>\n\n\n\n
    45. If resistance and voltage are doubled, the current will be:
      <\/mark><\/strong>a) Same
      b) Doubled
      c) Halved
      d) Quadrupled
      Answer:<\/strong> a) Same
      Explanation:<\/strong> , both numerator and denominator doubled cancel out.<\/li>\n\n\n\n
    46. The unit of electrical power is:
      <\/mark><\/strong>a) Volt
      b) Watt
      c) Ampere
      d) Ohm
      Answer:<\/strong> b) Watt
      Explanation:<\/strong> Power is measured in watts.<\/li>\n\n\n\n
    47. The resistance of a wire at temperature is given by:
      <\/mark><\/strong>a)
      b)
      c)
      d)
      Answer:<\/strong> a)
      Explanation:<\/strong> Resistance increases linearly with temperature for metals.<\/li>\n\n\n\n
    48. The resistance of a wire is 5 \u03a9 at 20\u00b0C. Its resistance at 40\u00b0C if per \u00b0C will be:
      <\/mark><\/strong>a) 5.4 \u03a9
      b) 6 \u03a9
      c) 4.5 \u03a9
      d) 7 \u03a9
      Answer:<\/strong> a) 5.4 \u03a9
      Explanation:<\/strong> .<\/li>\n\n\n\n
    49. The current density is related to current and cross-sectional area by:<\/mark><\/strong>
      a)
      b)
      c)
      d)
      Answer:<\/strong> a)
      Explanation:<\/strong> Current density is current per unit area.<\/li>\n\n\n\n
    50. The resistance of a wire depends on:
      <\/mark><\/strong>a) Only length
      b) Only cross-sectional area
      c) Length and cross-sectional area
      d) Neither length nor area
      Answer:<\/strong> c) Length and cross-sectional area
      Explanation:<\/strong> Resistance .<\/li>\n\n\n\n
    51. Ohm\u2019s law states that:
      <\/mark><\/strong>a)
      b)
      c)
      d)
      Answer:<\/strong> a)
      Explanation:<\/strong> Voltage across a resistor is proportional to current.<\/li>\n\n\n\n
    52. In a series circuit with resistors 2 \u03a9, 3 \u03a9, and 5 \u03a9, the total resistance is:
      <\/mark><\/strong>a) 10 \u03a9
      b) 15 \u03a9
      c) 1 \u03a9
      d) 0.3 \u03a9
      Answer:<\/strong> a) 10 \u03a9
      Explanation:<\/strong> Total resistance in series is sum <\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"

      Correction: \u03a9 So Answer is b) 11 \u03a9.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8,19],"tags":[15723,15725,15481,15700,15715,15724,15717,15720,15710,15718,15714,15721,15712,15465,15716,15713,15536,15479,15474,15467,15483,15472,15592,15456,15478,15719,15722,15711,15469,15480],"class_list":{"0":"post-12589","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-physics","7":"category-science","8":"tag-ammeter-and-voltmeter","9":"tag-circuit-diagram","10":"tag-competitive-exam-physics","11":"tag-conductors-and-insulators","12":"tag-current-electricity-in-physics","13":"tag-current-electricity-problems","14":"tag-electric-charge","15":"tag-electric-current","16":"tag-electric-energy","17":"tag-electric-power","18":"tag-electrical-circuits","19":"tag-electrical-measurements","20":"tag-kirchhoffs-laws","21":"tag-mcqs-for-physics-exam","22":"tag-ohms-law","23":"tag-parallel-circuits","24":"tag-physics-formulas","25":"tag-physics-learning","26":"tag-physics-mcqs","27":"tag-physics-preparation-material","28":"tag-physics-questions-and-answers","29":"tag-physics-quiz","30":"tag-physics-revision","31":"tag-physics-study-material","32":"tag-psc-physics-mcqs","33":"tag-resistance","34":"tag-resistivity","35":"tag-series-circuits","36":"tag-ssc-physics-mcqs","37":"tag-upsc-physics-mcqs"},"_links":{"self":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/12589","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/comments?post=12589"}],"version-history":[{"count":2,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/12589\/revisions"}],"predecessor-version":[{"id":12596,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/12589\/revisions\/12596"}],"wp:attachment":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/media?parent=12589"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/categories?post=12589"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/tags?post=12589"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}