UPSC Physics Electric Current and Magnetism Question Bank

done Electricity, Magnetism and Light Total Questions - 50

• question_answer1)
  The polarity of an unmarked horse shoe magnet can be determined by using                           [NDA]
  A)
  a charged glass rod done clear
  B)
  a magnetic compass done clear
  C)
  an electroscope done clear
  D)
  another unmarked bar magnet done clear
  View Solution play_arrow

• question_answer2)
  The earth's magnetic field is approximately [NDA]
  A)
  1 Tesla  done clear
  B)
  2 Gauss done clear
  C)
  \[{{10}^{4}}\] Tesla                 done clear
  D)
  1 Gauss done clear
  View Solution play_arrow

• question_answer3)
  An electric lamp of 100 watt is used for 10 hours per day. The 'units' of energy consumed in one day by the lamp is [NDA]
  A)
  1 unit done clear
  B)
  0.1 unit done clear
  C)
  10 units             done clear
  D)
  100 units done clear
  View Solution play_arrow

• question_answer4)
        The main power supply in India is at 220 V, whereas that in the US is at 110 V. Which one among the following statements in this regard is correct?                               [NDA]
  A)
  110 V is safer but more expensive to maintain done clear
  B)
  110 V is safer and cheaper to maintain done clear
  C)
  110 V leads to lower power loss done clear
  D)
  110 V works better at higher latitudes done clear
  View Solution play_arrow

• question_answer5)
        Two pieces of conductor of same material and of equal length are connected in series with a cell. One of the two pieces has cross-sectional area double that of the other. Which one of the following statements is correct in this regard?                               [NDA]
  A)
  The thicker one will allow stronger current to pass through it. done clear
  B)
  The thinner one would allow stronger current to pass through it. done clear
  C)
  Same amount of electric current would pass through both the pieces producing more heat in the thicker one. done clear
  D)
  Same amount of electric current would pass through both the pieces producing more heat in the thinner one. done clear
  View Solution play_arrow

• question_answer6)
  Magnetism of a bar magnet can be destroyed if it is [NDA]

  I. kept in the magnetic meridian.

  II. placed in a direction opposite to that of the Earth's horizontal intensity.

  III. heated to a temperature known as Curie temperature.

  Select the correct answer using the code given below
  A)
  I and III only      done clear
  B)
  II only done clear
  C)
  II and III only     done clear
  D)
  I, II and III done clear
  View Solution play_arrow

• question_answer7)
        What is the order of magnitude of electric resistance of the human body (dry)?                                    [IAS Prelim]
  A)
  \[{{10}^{2}}\] ohm                  done clear
  B)
       \[{{10}^{4}}\] ohm done clear
  C)
  \[{{10}^{6}}\] ohm                  done clear
  D)
       \[{{10}^{8}}\] ohm done clear
  View Solution play_arrow

• question_answer8)
        A wire of resistance 16 W is bent in the form of a circle. What is the effective resistance between diametrically opposite points?                                    [NDA]
  A)
  1 W                  done clear
  B)
       2 W done clear
  C)
  4 W           done clear
  D)
       8 W done clear
  View Solution play_arrow

• question_answer9)
        Fluorescent tubes are fitted with a choke. The choke coil:                              [IAS Prelim]
  A)
  steps up the line voltage done clear
  B)
  steps-down the line voltage done clear
  C)
  reduces current in the circuit done clear
  D)
  chokes low frequency current done clear
  View Solution play_arrow

• question_answer10)
  Electrically charged particles from space travelling at speeds of several hundred km/sec can severely harm living beings if they reach the surface of the Earth. What prevents them from reaching the surface of the Earth? [IAS Prelim]
  A)
  The Earth's magnetic field diverts them towards its poles done clear
  B)
  Ozone layer around the Earth reflects them back to outer space done clear
  C)
  Moisture in the upper layers of atmosphere prevents them from reaching the surface of the Earth done clear
  D)
  None of the statements [a], [b] and [c] given above is correct done clear
  View Solution play_arrow

• question_answer11)
  Match List I with List II and select the correct answer using the code given below the Lists: [NDA]

  	List I(Magnet)		List II(Property)
  A.	Artificial magnet	1.	Long lived
  B.	Permanent magnet	2.	Last for infinitely long period
  C.	Temporary magnet	3.	Short lived
  D.	Earth as a magnet	4.	Induced magnet

   
  A)
  A-3,   B-1,   C-4,   D-2 done clear
  B)
  A-3,   B-4,   C-1,   D-2 done clear
  C)
  A-2,   B-1,   C-4,   D-3 done clear
  D)
  A-2,   B-4,   C-1,   D-3 done clear
  View Solution play_arrow

• question_answer12)
        Consider the following statements regarding a motor car battery:                               [IAS Prelim]

  1. The voltage is usually 12V.

  2. Electrolyte used is hydrochloric acid.

  3. Electrodes are lead and copper.

  4. Capacity is expressed in ampere-hour.

  Which of the above statements are correct?
  A)
        1 and 2             done clear
  B)
       2 and 3 done clear
  C)
  3 and 4             done clear
  D)
       1 and 4 done clear
  View Solution play_arrow

• question_answer13)
        From a power station, the power is transmitted at a very high voltage because -
  A)
  it is generated only at high voltage done clear
  B)
  it is cheaper to produce electricity at high voltage done clear
  C)
  electricity at high voltage is less dangerous done clear
  D)
  there is less loss of energy in transmission at high voltage done clear
  View Solution play_arrow

• question_answer14)
        What is the number of neutral points for a bar magnet with its north pole pointing geographical north?                           [NDA]
  A)
  Zero                  done clear
  B)
       One done clear
  C)
  Two           done clear
  D)
       Infinite done clear
  View Solution play_arrow

• question_answer15)
        Magnets attract magnetic substances are iron, nickel, cobalt, etc. They can also repel                           [NDA]
  A)
  paramagnetic substances done clear
  B)
  ferromagnetic substances done clear
  C)
  diamagnetic substances done clear
  D)
  non-magnetic substances done clear
  View Solution play_arrow

• question_answer16)
        Which one among the following is the correct order of power consumption for light of equal intensity?                            [NDA]
  A)
  CFL tube < Fluorescent tube < Incandescent bulb < Light emitting diode done clear
  B)
  Light emitting diode < CFL tube < Fluorescent tube < Incandescent bulb done clear
  C)
  CFL tube < Fluorescent tube < Light emitting diode < Incandescent bulb done clear
  D)
  Incandescent bulb < Light emitting diode < Fluorescent tube < CFL tube done clear
  View Solution play_arrow

• question_answer17)
        Two pieces of metallic wire having equal lengths and equal volume placed in air have different resistances. The two wires must                                    [NDA]
  A)
  have different cross-sections done clear
  B)
  have different temperatures done clear
  C)
  be of different materials done clear
  D)
  be of same density done clear
  View Solution play_arrow

• question_answer18)
        Graphene is frequently in news recently. What is its importance?                               [IAS Prelim]

  1. It is a two-dimensional material and has good electrical conductivity.

  2. It is one of the thinnest but strongest materials tested so far.

  3. It is entirely made of silicon and has high optical transparency.

  4. It can be used as 'conducting electrodes' required for touch screens, LCDs and organic LEDs.

  Which of the statements given above are correct?
  A)
  1 and 2 only      done clear
  B)
       3 and 4 only done clear
  C)
  1, 2 and 4 only done clear
  D)
       1, 2, 3 and 4 done clear
  View Solution play_arrow

• question_answer19)
        If the electrical resistance of a typical substance suddenly drops to zero then the substance is called                                [NDA]        
  A)
                                                                                                                                              superconductor done clear
  B)
       semiconductor done clear
  C)
  conductor          done clear
  D)
       insulator done clear
  View Solution play_arrow

• question_answer20)
       

  Which one of the following is correct?

  Lightning is formed, when                        [NDA]

  A)
  similar charges of electricity rush towards each other and then get repelled done clear
  B)
  clouds strike against impurities in air and the friction bums up these impurities done clear
  C)
  strong opposite charges in different clouds break down the resistance offered by intervening air done clear
  D)
  water vapour produces electricity in the clouds done clear
  View Solution play_arrow

• question_answer21)
       

  Consider the following statements:

  An ordinary light bulb has a rather short life because the:                             [IAS Prelim]

  1. filament wire is not uniform.

  2. bulb cannot be evacuated completely.

  3. wires supporting the filament melt at high temperatures.

  Which of the above statements are correct?
  A)
  1 and 3             done clear
  B)
       2 and 3 done clear
  C)
  1 and 2             done clear
  D)
       1, 2 and 3 done clear
  View Solution play_arrow

• question_answer22)
        Consider the following statements regarding a motor car battery:                               [IAS Prelim]

  1. The voltage is usually 12V.

  2. Electrolyte used is hydrochloric acid.

  3. Electrodes are lead and copper.

  4. Capacity is expressed in ampere-hour.

  Which of the above statements are correct?
  A)
  1 and 2                         done clear
  B)
  2 and 3 done clear
  C)
  3 and 4 done clear
  D)
       1 and 4 done clear
  View Solution play_arrow

• question_answer23)
  In which one of the following cases Ohm's law is not valid? [NDA]
  A)
  Wire bound resistor done clear
  B)
  Potentiometer done clear
  C)
  Junction diode done clear
  D)
  Electric bulb done clear
  View Solution play_arrow

• question_answer24)
        Which one of the statements given below is not correct?                               [NDA]
  A)
  A vertical plane passing through the axis of a freely suspended magnet is called the magnetic meridian done clear
  B)
  A vertical plan passing through the axis of rotation of the Earth is called the geographical meridian done clear
  C)
  The degree to which the magnetic field can penetrate a medium is known as the relative permeability of the medium done clear
  D)
  The relative permeability is not a dimensionless quantity done clear
  View Solution play_arrow

• question_answer25)
        A current I flows through a potential difference V in an electrical circuit containing a resistance R. The product of V and I, i.e., VI may be understood as                         [NDA]
  A)
  resistance R done clear
  B)
  heat generated by the circuit done clear
  C)
  thermal power radiated by the circuit done clear
  D)
  rate of change of resistance done clear
  View Solution play_arrow

• question_answer26)
        A coin in a beaker filled with water appears raised. This phenomenon occurs because of the property of                          [NDA]
  A)
  reflection of light done clear
  B)
  refraction of light done clear
  C)
  total internal reflection of light done clear
  D)
  interference of light done clear
  View Solution play_arrow

• question_answer27)
        When light waves travel from air to glass, which variables are affected?                                  [NDA]
  A)
  Wavelength, frequency and velocity done clear
  B)
  Velocity and frequency only done clear
  C)
  Wavelength and frequency only done clear
  D)
  Wavelength and velocity only done clear
  View Solution play_arrow

• question_answer28)
       

  Consider the following statement:

  The principle of total internal reflection is applicable to explain the                             [NDA]

  1. Formation of mirage in desert.

  2. Formation of image in microscope.

  3. Colour of evening sky.

  4. Operation of optical fibres.

  Which of the statement given above are correct?
  A)
  1 and 4 done clear
  B)
       3 and 4 done clear
  C)
  2 and 3             done clear
  D)
       1 and 2 done clear
  View Solution play_arrow

• question_answer29)
        When an optician prescribes a - 5D lens, what does it mean?                        [NDA]
  A)
  Concave lens of 20 cm focal length done clear
  B)
  Convex lens of 5 cm focal length done clear
  C)
  Concave lens of 5 cm focal length done clear
  D)
  Convex lens of 5 cm focal length done clear
  View Solution play_arrow

• question_answer30)
        Which one of the following is the correct angle between the incident and reflected rays when a ray of light incident normally on a plane mirror?                           [NDA]
  A)
  \[{{180}^{o}}\]                       done clear
  B)
       \[90{}^\circ \] done clear
  C)
  \[45{}^\circ \]               done clear
  D)
       \[0{}^\circ \]             done clear
  View Solution play_arrow

• question_answer31)
        A spherical air bubble is embedded in a piece of glass. For a ray of light passing through the bubble, it behaves like a                               [NDA]
  A)
  converging lens done clear
  B)
  diverging lens done clear
  C)
  plano-converging lens done clear
  D)
  plano-diverging lens done clear
  View Solution play_arrow

• question_answer32)
        What is the phenomenon of the moon to appear bigger in size as it approaches the horizon, called?                                [NDA]
  A)
  Atmospheric refraction of light done clear
  B)
  Diffraction of light done clear
  C)
  Scattering of light done clear
  D)
  Total internal reflection of light by water vapours done clear
  View Solution play_arrow

• question_answer33)
        Which one among the following is used to make periscope?                           [NDA]
  A)
  Concave lens     done clear
  B)
       Concave mirror done clear
  C)
  Plane mirror      done clear
  D)
  None of the above done clear
  View Solution play_arrow

• question_answer34)
        What is the essential difference between a terrestrial telescope and an astronomical telescope?                           [NDA]
  A)
  One of the lenses in a terrestrial telescope is concave done clear
  B)
  The final image formed in a terrestrial telescope is virtual done clear
  C)
  A terrestrial telescope forms an erect image while an astronomical telescope forms an inverted image done clear
  D)
  A terrestrial telescope forms an inverted image while an a astronomical telescope forms an erect image done clear
  View Solution play_arrow

• question_answer35)
        A ray of light is incident normally on one of the faces of right angled isosceles prism as shown above. It undergoes total internal reflection from hypotenuse. Which one of the following is the minimum refractive index of the material of the prism?                               [NDA]
  A)
  1.0                    done clear
  B)
       1.33 done clear
  C)
  1.414         done clear
  D)
       1.6 done clear
  View Solution play_arrow

• question_answer36)
        A far-sighted person has a near point at 100 cm. What must be the power of the correcting lens?                                   [NDA]
  A)
  - 0.8 D             done clear
  B)
       - 3.0 D done clear
  C)
  + 0. 8D             done clear
  D)
       + 3.0 D done clear
  View Solution play_arrow

• question_answer37)
        An object is kept 5 cm in front of a concave mirror of focal length 15 cm. What will be the nature of the image?                         [NDA]
  A)
  Virtual, not magnified done clear
  B)
  Virtual, magnified done clear
  C)
  Real, not magnified done clear
  D)
  Real, magnified done clear
  View Solution play_arrow

• question_answer38)
        The ratio of the focal length of the objective to the focal length of the eyepiece is greater than one for                            [NDA]
  A)
  a microscope done clear
  B)
  a telescope done clear
  C)
  both microscope and telescope) done clear
  D)
  neither microscope nor telescope done clear
  View Solution play_arrow

• question_answer39)
        In the figure shown above, \[{{L}_{1}}\] and \[{{L}_{2}}\], are two lenses and are kept along the same axis. A parallel beam of light falling on \[{{L}_{1}}\] leaves \[{{L}_{2}}\] as a parallel beam: [NDA]  

  Consider the following statements.

  1. Both \[{{L}_{1}}\] and \[{{L}_{2}}\] can be convex lenses.

  2. The distance between the two lenses can be equal to sum of their focal lengths.

  Which of the statements given above is/are correct?
  A)
  Only 1                           done clear
  B)
  Only 2 done clear
  C)
  Both 1 and 2    done clear
  D)
  Neither 1 nor 2 done clear
  View Solution play_arrow

• question_answer40)
        Refractive index of an optical medium changes with                        [NDA]

  1. the nature of the medium.

  2. the change in the angle of incidence of the ray.

  3. colour of the incident ray.

  Select the correct answer using the code given below:
  A)
  1 and 3 only      done clear
  B)
       2 and 3 only done clear
  C)
  1 and 2 only      done clear
  D)
       1, 2 and 3 done clear
  View Solution play_arrow

• question_answer41)
        Yellow colour light is used as fog light because yellow colour                         [NDA]
  A)
  light is most scattered by fog done clear
  B)
  has the longest wavelength among all colours done clear
  C)
  has the longest wavelength among all colours except red and orange but the red colour is already used for brake light and stop light whereas orange colour is avoided due to its similarity with red done clear
  D)
  has the shortest wavelength among all colours not already reserved for other purpose done clear
  View Solution play_arrow

• question_answer42)
        A refracting telescope consists of                           [NDA]
  A)
  one concave mirror and one convex lens done clear
  B)
  two convex lenses of equal focal length done clear
  C)
  two concave mirrors of different focal lengths done clear
  D)
  two convex lenses of unequal focal lengths done clear
  View Solution play_arrow

• question_answer43)
        An object is placed at the focus of a concave mirror. The image will be                                  [NDA]
  A)
  real, inverted, same size at the focus done clear
  B)
  real, upright, same size at the focus done clear
  C)
  virtual, inverted, highly enlarged at infinity done clear
  D)
  real, inverted, highly enlarged at infinity done clear
  View Solution play_arrow

• question_answer44)
        Consider the following statements                          [CDS]

  1. Clear sky appears blue due to poor scattering of blue wavelength of visible light.

  2. Red part of light shows more scattering than blue light in the atmosphere.

  3. In the absence of atmosphere, there would be no scattering of light and sky will look black.

  Which of the statements given above is/are correct?
  A)
  Only 1               done clear
  B)
       1 and 2 done clear
  C)
  Only 3       done clear
  D)
       All of these done clear
  View Solution play_arrow

• question_answer45)
       

  Assertion [A]: A myopic person is advised to use concave lens.

  Reason [R]: The eye lens of a myopic person focuses the parallel rays coming from distant objects in front of the retina. [NDA]

   
  A)
  Both A and R are individually true and R is the correct explanation of A done clear
  B)
  Both A and R are individually true but R is NOT the correct explanation of A done clear
  C)
  A is true but R is false done clear
  D)
  A is false but R is true done clear
  View Solution play_arrow

• question_answer46)
        If the focal length of the biconvex lens is 25 cm, then the power of the lens will be                               [NDA]
  A)
  + 4 dioptre done clear
  B)
       - 4 dioptre done clear
  C)
  + 0.04 dioptre     done clear
  D)
       - 0.04 dioptre done clear
  View Solution play_arrow

• question_answer47)
        Two thin convex lenses of focal lengths 4 cm and 8 cm are separated by a distance of 4 cm in air. The combination will have the focal length                           [NDA]
  A)
  4 cm          done clear
  B)
       8 cm done clear
  C)
  12 cm               done clear
  D)
       32 cm done clear
  View Solution play_arrow

• question_answer48)
       

  Assertion [A]: Convex mirror is used as a driver mirror.

  Reason [R]: Images formed by convex mirror are diminished in size. [NDA]

  A)
  Both A and R are individually true and R is the correct explanation of A done clear
  B)
  Both A and R are individually true but R is NOT the correct explanation of A done clear
  C)
  A is true but R is false done clear
  D)
  A is false but R is true done clear
  View Solution play_arrow

• question_answer49)
  Match the column -I and Column - II.

  	Column-I		Column-II
  A.	Myopia	P.	Convex lens
  B.	Hypermetropia	Q.	Concave lens
  C.	Presbyopia	R.	Cylindrical lens
  D.	Astigmatism	S.	Bifocal Lens

  A)
  A-P;   B-Q;   C-S;   D-R done clear
  B)
  A-P;   B-Q;   C-R;   D-S                           done clear
  C)
  A-Q;   B-P;   C-S;   D-R                           done clear
  D)
  A-Q;   B-P;   C-R;   D-S                              done clear
  View Solution play_arrow

• question_answer50)
       

  Assertion [A]: A person stands at a distance of 1m in front of a concave mirror. If the radius of curvature of the mirror is 4m, the image of the person lies at a distance 2m behind the mirror.

  Reason [R]: The general mirror equation confirms the location of the image from the mirror and it could be a real image. [NDA]

  A)
  Both A and R are individually true and R is the correct explanation of A done clear
  B)
  Both A and R are individually true but R is NOT the correct explanation of A done clear
  C)
  A is true but R is false done clear
  D)
  A is false but R is true done clear
  View Solution play_arrow