JEE Physics Electric Charges and Fields MCQs Set B

Question:

• a) 10^–3 C
• b) 10^–4 C
• c) 10^–2 C
• d) 10^–1 C

Answer: 10^–3 C

Question:

• a) Both
• b)

  

• c)

  

• d) None of these

Answer: Both

Question:

• a)

  

• b)

  

• c)

  

• d) Any of these

Answer:

Question: A charge q is situated at the centre of a cube. Electric flux through one of the faces of the cube is

• a)

  

• b)

  

• c)

  

• d) Zero

Answer:

Question: A charge Q is placed at the centre of the open end of a cylindrical vessel. Electric flux through the surface of the vessel is

• a)

  

• b)

  

• c)

  

• d) Zero

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d) Zero

Answer:

Question: Total electric flux associated with unit positive charge in vacuum is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: A charged body has an electric flux F associated with it. Now if the body is placed inside a conducting shell then the electric flux outside the shell is

• a) Equal to F
• b) Less than F
• c) Greater than F
• d) Zero

Answer: Equal to F

Question: A cylinder of radius R and length L is placed in a uniform electric field E parallel to the cylinder axis. The outward flux over the surface of the cylinder is given by

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: A rectangular surface of sides 10 cm and 15 cm is placed inside a uniform electric field of 25 V/m, such that the surface makes an angle of 30° with the direction of electric field. Find the flux of the electric field through the rectangular surface

• a) 0.1875 Nm²/C
• b) 0.1675 N/m²C
• c) Zero
• d) 0.1075 Nm²/C

Answer: 0.1875 Nm²/C

Question:

• a) 100 units
• b) 10 units
• c) 30 units
• d) 40 units

Answer: 100 units

Question: The electric field in a region is radially outward and at a point is given by E = 250 r V/m (where r is the distance of the point from origin). Calculate the charge contained in a sphere of radius 20 cm centred at the origin

• a) 2.22 × 10^–10 C
• b) 2.22 × 10^–8 C
• c) 2.22 × 10^–6 C
• d) Zero

Answer: 2.22 × 10^–10 C

Question:

• a) 0.3 × 8 × 10³
• b) 2 × 8 × 10³
• c) Zero
• d) 8 × 10⁶ × 6

Answer: 0.3 × 8 × 10³

Question: A charge Q is kept at the corner of a cube. Electric flux passing through one of those faces not touching that charge is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: An isolated solid metal sphere of radius R is given an electric charge. Which of the graphs below best shows the way in which the electric field E varies with distance x from the centre of the sphere?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: An isolated solid metal sphere of radius R is given an electric charge. Which of the graphs below best shows the way in which the electric field E varies with distance x from the centre of the sphere?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question:

• a) 1 : 1
• b) 4 : 3
• c) 2 : 1
• d) 1 : 2

Answer: 1 : 1

Question: Consider an atom with atomic number Z as consisting of a positive point charge at the centre and surrounded by a distribution of negative electricity uniformly distributed within a sphere of radius R. The electric field at a point inside the atom at a distance r from the centre is

• a)

  

• b)

  

• c)

  

• d) Zero

Answer:

Question:

• a) 5.62 × 10⁷
• b) 562 × 10⁷
• c) 0.0562 × 10⁷
• d) 0.562 × 10⁷

Answer: 5.62 × 10⁷

Question:

• a) Zero
• b)

  

• c)

  

• d)

  

Answer: Zero

Question: For two infinitely long charged parallel sheets, the electric field at P will be

• a) Zero
• b)

  

• c)

  

• d) None of these

Answer: Zero

Question: Select the correct statement about electric charge

• a) Charge on a body is always integral multiple of a certain charge called charge of electron
• b) Charge on a body is always positive or zero
• c) Charge of a particle increases with increase in its velocity
• d) Charge can be converted into energy and energy can be converted into charge

Answer: Charge on a body is always integral multiple of a certain charge called charge of electron

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d) Zero

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d) Zero

Answer:

Question:

• a)

  

• b) Both trajectories are equally curved but in opposite direction
• c) Proton trajectory is more curved
• d) Both trajectories are equally curved and in same direction

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Which of the following is not true about electric charge?

• a) A particle having zero rest mass can have non zero charge
• b) A particle having nonzero rest mass can have zero charge
• c) Charge on an isolated system is always conserved
• d) Charge is a scalar quantity

Answer: A particle having zero rest mass can have non zero charge

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Two positive point charges of unequal magnitude are placed at a certain distance apart. A small positive test charge is placed at null point, then

• a) The test charge is in unstable equilibrium
• b) The test charge is in neutral equilibrium
• c) The test charge is in stable equilibrium
• d) The test charge is not in equilibrium

Answer: The test charge is in unstable equilibrium

Question:

• a) C
• b) A
• c) B
• d) All have same charge to mass ratio

Answer: C

Question: An infinite line charge is at the axis of a cylinder of length 1 m and radius 7 cm. If electric field at any point on the curved surface of cylinder is 250 NC^–1, then net electric flux through the cylinder is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) Zero
• b) Upwards
• c) Towards plate B
• d) Towards plate A

Answer: Zero

Question: Which of the following is not the unit of charge?

• a) Farad
• b) Coulomb
• c) Stat coulomb
• d) Faraday

Answer: Farad

Question: If two charges of 1 coulomb each are placed 1 km apart, then the force between them will be

• a) 9 × 10³ N
• b) 9 × 10^–3 N
• c) 9 × 10^–4 N
• d) 10^–6 N

Answer: 9 × 10³ N

Question: The magnitude of electric field strength E such that an electron placed in it would experience an electrical force equal to its weight is given by

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) Both negative
• b) Both positive
• c)

  

• d)

  

Answer: Both negative

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Electric charge q, q and –2q are placed at the corners of an equilateral triangle ABC of side L. The magnitude of electric dipole moment of the system is

• a)

  

• b) 4qL
• c) 2qL
• d) qL

Answer:

Question:  A given charge situated at a certain distance from a short electric dipole in the end on position experience a force F. If the distance of the charge is doubled, the force acting on the charge will be

• a)

  

• b)

  

• c)

  

• d) 2F

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer: