Physics Selected Questions and Answers Set 5

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physics science solved questions and answers previous years question and answer civil services entranciology set 5

Q.1:- Which one of the following phenomena is used in optical fibres ?

  1. Scattering
  2. Successive Reflection
  3. Refraction
  4. Total Internal Reflection

Ans:- (d) Total Internal Reflection

Q.2:- The human eyes has a lens which has a ?

  1. Soft portion at its centre
  2. Hard surface
  3. Varying refractive index
  4. Constant refractive index

Ans:- (d) Constant refractive index

Q.3:- Longitudinal waves do not exhibit ?

  1. Refraction
  2. Reflection
  3. Diffraction
  4. Polarization

Ans:- (d) Polarization

Q.4:- The image formed on the retina of a human eye is ?

  1. Virtual and inverted
  2. Virtual and erect
  3. Real and erect
  4. Real and inverted

Ans:- (d) Real and inverted

Q.5:- Cylindrical lens is used by a person suffering from ?

  1. Astigmatism
  2. Myopia
  3. Hypermetropia
  4. Presbyopia

Ans:- (a) Astigmatism

Q.6:- The phenomenon of splitting white light into seven colours is called ?

  1. Reflection
  2. Refraction
  3. Refractive index
  4. Dispersion

Ans:- (d) Dispersion

Q.7:- The resistance of material increases with temperature. It is a ?

  1. Metal
  2. Insulator
  3. Semiconductor
  4. None of these

Ans:- (a) Metal

Q.8:- Electron volt (eV) is a unit of ?

  1. Energy
  2. Potential
  3. Current
  4. Charge

Ans:- (a) Energy

Q.9:- The resistance of an ideal voltmeter is ?

  1. Zero
  2. Very low
  3. Very high
  4. Infinite

Ans:- (a) Zero

Q.10:- Equal charges are given to two spheres of different radii. The potential will be ?

  1. More on smaller sphere
  2. More on bigger sphere
  3. Equal on both the sphere
  4. None of these

Ans:- (a) More on smaller sphere

Q.11:- Good resistance coils are made of ?

  1. Copper
  2. Manganin
  3. Gold
  4. Silver

Ans:- (b) Manganin

Q.12:- The filament of bulb is of ?

  1. Mercury
  2. Copper
  3. Tungsten
  4. None of these

Ans:- (c) Tungsten

Q.13:- A thermoelectric refrigerator works on ?

  1. Jule Effect
  2. Seebeck Effect
  3. Peltier Effect
  4. None of these

Ans:- (c) Peltier Effect

Q.14:- A small piece of an unmagnetised material gets repelled when it is brought near a powerful magnet the material is ?

  1. Paramagnetic
  2. Diamagnetic
  3. Ferromagnetic
  4. Non Magnetic

Ans:- (b) Diamagnetic

Q.15:- A source of magnetic field is ?

  1. A static electric charge
  2. A moving electric charge
  3. A current loop
  4. Both (b) and (c)

Ans:- (d) Both (b) and (c)

Q.16:- Which of the following is most suitable for the core of an electromagnet ?

  1. Air
  2. Soft Iron
  3. Steel
  4. None of these

Ans:- (b) Soft Iron

Q.17:- A diode as a rectifier converts ?

  1. AC to DC
  2. DC to AC
  3. Varying DC into constant DC
  4. High Voltage into low voltage and vice-versa

Ans:- (a) AC to DC

Q.18:- The conductivity of a super-conductor is ?

  1. Infinite
  2. Small
  3. Zero
  4. Large

Ans:- (a) Infinite

Q.19:- The cause of fractional atomic weights of elements is the presence of ?

  1. Isobars
  2. Isotopes
  3. Isotones
  4. None

Ans:- (b) Isotopes

Q.20:- With the rise of temperature, the specific resistance of semiconductor ?

  1. Increases
  2. Remains Unchanged
  3. Decreases
  4. None of these

Ans:- (c) Decreases

Q.21:- Cathode rays enter an electric field normal to the lines of force. Then their path in the electric field is ?

  1. Straight Line
  2. Ellipse
  3. Circle
  4. Parabola

Ans:- (d) Parabola

Q.22:- At zero degree kelvin a piece of germinium ?

  1. Becomes semiconductor
  2. Becomes good conductor
  3. Becomes bad conductor
  4. None of these

Ans:- (c) Becomes bad conductor

Q.23:- Which of the following is not a semiconductor ?

  1. Germinium
  2. Silicon
  3. Arsenic
  4. All of these

Ans:- (c) Arsenic

Q.24:- The space waves which are affected seriously by atmospheric conditions are ?

  1. MF0
  2. HF
  3. VHF
  4. UHF

Ans:- (d) UHF

Q.25:- The technique of collecting information about an object from a distance without making physical contact with it is ?

  1. Remote Sensing
  2. Remote Control
  3. Remote Accessing
  4. Space Shuttle

Ans:- (a) Remote Sensing


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