Skip to main content

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)


  by    www.advguruji.blogspot.com
Labels:

Comments

Post a Comment

Popular posts from this blog

Age problems (for practice) | class 10 mathematics | advguruji | Physics Advocate

Linear Equations Q1. Ten years ago, father was twelve times as old as his son and ten years hence, he will be twice as old as his son will be. Find their present ages. Ans. Present age of father = 34 years          Present age of son = 12 years Q2. Three years ago, Priya's mother was six times older than her. Four years from now, Priya's mother will be one year older than thrice her age. Find the present age of Priya and her mother. Ans.  Present age of Priya = 8 years       Present age of mother = 33 years Q3. Five years ago, Rakesh was five times younger than his mother. Ten years from now, his age will be half of his mother's age. Find the present age of Rakesh and his mother. Ans. Present age of Rakesh = 10 years      Present age of mother = 30 years Q4.           (equation in one variable) A  is elder to  B  by two years. A's father  F  is twice as old as  A .  ...
1 comment
Read more

Problems on acceleration due to gravity and variation of acceleration due to gravity, class 11 | Physics Advocate

Q1. Calculate the percentage decrease in the weight of a body when it is taken to a height of 40 km above the Earth's surface. Radius of Earth = 6,400 km Ans. 1.25% Q2. Calculate the depth below the surface of Earth where the acceleration due to gravity is 25% of its value at the Earth's surface. Take, radius of Earth = 6,400 km. Ans. 4.8 × 10⁶ m Q3. A body weighs 100N on Earth's surface. Calculate the gravitational force on the body at a height equal to one-fourth the radius of Earth. Ans. 64 N Q4. Calculate the percentage decrease in weight of a body when taken to a tunnel 38.4 km below the Earth's surface. Ans. 0.6% Q5. Calculate the height from the Earth's surface at which the acceleration due to gravity becomes 75% compared at Earth's surface. Take, radius of Earth = 6,400 km. Ans. 990 km ---------------------------------------------------------------------------------------------- EXTRA QUESTIONS Q6. Find the percentage increase in acceleration due to grav...
Post a Comment
Read more

Energy of electron in nth orbit of Hydrogen atom | Numericals by Physics Advocate

Q1. How much energy is needed to relocate an electron from first excited state to fourth excited state in an Hydrogen atom? Also, find the type of light needed in this process. Q2. Find the wavelength of light released when an electron jumped from 4th excited state to ground state in an Hydrogen atom. Also, name the series. Q3. Find the wavenumber of light released when an electron jumped from 5th excited state in bracket series (in H - atom). www.advguruji.blogspot.com Q4. An electron absorbed 2.55 eV energy and jumped from first excited state to nth excited state. Find n . Q5. when an electron jumped from second excited state to some different state, UV ray was released. Name the state and find the frequency of the UV ray. --------------------------------------------------------------------------------------------------- ANSWERS Ans1. 2.86 eV Ans2. 99 nm Ans3. 0.375 × 10⁶ m-¹ Ans4. n = 3 Ans5. 2.90 × 10¹⁵ Hz by    www.advguruji.blogspot.com
Post a Comment
Read more