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Electric charges and fields | MCQs | class 12 physics | advguruji/Physics Advocate

Best of Luck STUDENTS

Que1.
Two small conducting spheres of equal radius have charges 10μC & -20μC respectively placed at a distance R from each other. They experience force F1. If they are brought in contact and separated to the same distance, they experience force F2.  Ratio of F1 to F2 is ___

a) 1:2

b) 1:1

c) 2:1

d) 8:1

Pyaare bacchon, agar online study se headache hota hai toh dekh lena, aaram milega


Que2.
Electric field intensity at a point in between two parallel sheets with like charges of same surface charge densities σ is ___

a) σ/εo

b) zero

c) σ/2εo

d) none of these



Que3.
There exists an electric field of 2 N/C along y direction. The flux passing through the square of side 1 m placed in xy plane inside the electric field is -

a) Zero

b) 2 Nm²/C

c) 1 Nm²/C

d) √3 Nm²/C


Que4.
A mass of 20g has a charge of 3mC. It moves with a velocity of 20m/s and enters a region of electric field of 80N/C in the same direction as the velocity of the mass. The velocity of the mass after 3 seconds in this region is -

a) 80 m/s

b) 56 m/s

c) 50 m/s

d) 36 m/s


Que5.
At what separation should two equal charges, 1 Coulomb each, be placed so that the force between them equals the weight of a 50 kg person?
Take, g = 10 m/s²

a) 2√2  km

b) 4√2  km

c) 3√2  km

d) None of these


Que6.
A water particle of mass 10 milligram and having a charge of 15 μC, stays suspended in a room. What is the magnitude of electric field in the room and what is its direction?

a) 10/3  V/m (upward)

b) 10  V/m (downward)

c) 20  V/m (downward)

d) 20/3  V/m (upward)


Que7.
Two insulating spheres are rubbed against each other and placed 1 cm apart. If they attract each other with a force of 0.1 N. How many electrons were transferred from one sphere to the other during rubbing?

a) 0.21 × 10¹²

b) 0.625 × 10¹⁹

c) 0.062 × 10¹⁴

d) 0.42 × 10¹²
Comment down your thoughts :-)
-----------------------------------------------------------------------
         ANSWERS

ANS 1. d)
ANS 2. a)
ANS 3. a)
ANS 4. b)
ANS 5. c)
ANS 6. d)
ANS 7. a)


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