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# PhysicalGeneral Knowledge English Speaking/Writing Computer Skill SSC Railways State Level Teaching

Get quiz for Physical General Knowledge + English Speaking/Writing Computer Skill SSC Railways State Level Teaching Exams , SSC , Railways Exams CGL/MTS/CPO, CTET & GATE. Get Free Quiz, PDF notes, Live video and guidance.

Question1) 81.What causes the twinkling of stars?

[A] Atmospheric refraction of starlight

[B] Dispersion of starlight

[C] Scattering of starlight

[D] None

Option- ['A', 'B', 'C', 'D']

Explaination: Correct Answer: A [Atmospheric refraction of starlight]

Notes:

The twinkling of a star is due to atmospheric refraction of starlight. The starlight, on entering the earth’s atmosphere, undergoes refraction continuously before it reaches the earth.

Question2) 82.What is the distance between the focus and the pole of the mirror is known as?

[A] Centre of Curvature

[B] Focal length

[C] Mirror number

Option- ['A', 'B', 'C', 'D']

Explaination: Correct Answer: B [Focal length]

Notes:

The distance between the focus F and the pole P of the mirror is called the focal length of the mirror

Question3) 83.What is the phenomenon of bouncing back of light in the same medium on striking the surface of any object known as?

[A] Refraction

[B] Absorption

[C] Reflection

[D] Diffusion

Option- ['A', 'B', 'C', 'D']

Notes:

Reflection of light is the phenomenon of bouncing back of light in the same medium on striking the surface of any object.

Question4) 84.As per Ohm’s law, if the resistance of a conductor is doubled, what will be the effect on the current flowing through it?

[A] it gets doubled

[B] it gets halved

[C] it increases 4 times

[D] No change

Option- ['A', 'B', 'C', 'D']

Explaination: Correct Answer: B [it gets halved ]

Notes:

As per Ohm’s law, if the resistance of a conductor is doubled, the electric current flowing through it gets halved. As per Ohm’s Law: R = V/I where R= Resistance, V= Potential Difference, I = Current

Question5) 85.What of the following represents Ohm’s law (V= potential difference and I=current)?

[A] V = I 2

[B] V = 1/I

[C] V/I = constant

[D] None of the above

Option- ['A', 'B', 'C', 'D']

Explaination: Correct Answer: C [V/I = constant ]

Notes:

The potential difference, V, across the ends of a given metallic wire in an electric circuit is directly proportional to the current flowing through it, provided its temperature remains the same. This is called Ohm’s law. V/I =constant

Question6) 86.What is the S.I. unit of electric charge?

[A] Ampere

[B] Coulomb

[C] Joule

[D] Watt

Option- ['A', 'B', 'C', 'D']

Explaination: Correct Answer: B [Coulomb ]

Notes:

The SI unit of electric charge is coulomb (C), which is equivalent to the charge contained in nearly 6 × 1018 electrons.

Question7) 87.Which of the following is correct about EMF of a cell?

[A] it is the potential difference between the electrodes when current is flowing in the cell

[B] it is the drift velocity of the electrons when there is no current in the cell

[C] it is the potential difference between the electrodes when there is no current in the cell

[D] None of the above

Option- ['A', 'B', 'C', 'D']

Explaination: Correct Answer: C [it is the potential difference between the electrodes when there is no current in the cell]

Notes:

Emf is defined as the potential difference between electrodes when there is no current in the cell(cell is in open circuit).

Question8) 88.Which of the following is correct about magnetic field?

[A] Magnetic field has magnitude but no direction

[B] Magnetic field has both magnitude and direction

[C] Magnetic field may or may not have direction

[D] None of the above

Option- ['A', 'B', 'C', 'D']

Explaination: Correct Answer: B [Magnetic field has both magnitude and direction]

Notes:

Magnetic field is a quantity that has both direction and magnitude.

Question9) 89.Which is the direction of magnetic field inside a magnet?

[A] from south pole to north pole

[B] from north pole to south pole

[C] from north pole till centre of the magnet

[D] None of the above

Option- ['A', 'B', 'C', 'D']

Explaination: Correct Answer: A [from south pole to north pole]

Notes:

Inside the magnet, the direction of field lines is from its south pole to its north pole.

Question10) 90.Which of the following is correct about magnetic field lines?

[A] Magnetic field lines are closed curves

[B] Degree of closeness of the field lines shows the strength of the magnetic field

[C] Both a and b

[D] None of the above

Option- ['A', 'B', 'C', 'D'] 