Electric Charges and Electric Fields  MCQs

MCQs of Electric Charges and Electric Fields

Showing 31 to 40 out of 141 Questions
31.
Charge Q each is placed on (n - 1) corners of a regular polygon of sides n. The distance of each corner from the centre of polygon is r. The electric field at its centre is _____ .
(a) kQr2
(b) (n - 1) kQr2
(c) n(n - 1) kQr2
(d) (n - 1)n kQr2
Answer:

Option (c)

32.
The number of electric field of lines emerging from 1 C charge is ______ . (ε = 8.85 × 10-12 MKS)
(a) 9 × 109
(b) 8.85 × 102
(c) 1.13 × 1011
(d) infinite
Answer:

Option (c)

33.
When 1019 electron are removed from a neutral metal plate through some process, the charge on it becomes _____.
(a) -1.6 C
(b) +1.6 C
(c) 109 C
(d) 10-19 C
Answer:

Option (b)

34.
A charge Q is placed at the centre of a cube. The electric flux emerging from any one surface of the cube is _____ .
(a) Qε0
(b) Q2ε0
(c) Q4ε0
(d) Q6ε0
Answer:

Option (a)

35.
In 1g of a solid, there are 5 × 1021 atoms. If one electron removed from 0.01% atoms of the solid, the charge gined by the solid is _____ . ( Here electronic charge = 1.6 × 10-19 C)
(a) + 0.08 C
(b) + 0.8 C
(c) - 0.08 C
(d) -0.8 C
Answer:

Option (a)

36.
Electrostatic force between two electrons 1 cm apart is _____ N.
(a) 5.5 × 10-67
(b) 5.5 × 10-24
(c) 2.3 × 10-24
(d) 2.3 × 10-67
Answer:

Option (c)

37.
Two identical spheres with charges 4q and -2q are kept at some distance apart exert a force F on each other. If they are made to touch each other and replaced at their old positions, the force between them will be _____ .
(a) 19F
(b) 18F
(c) 98F
(d) 89F
Answer:

Option (b)

38.
Charges 2Q and -Q are placed as shown in the figure. The point at which electric field intensity is zero will be _____ .
(a) somewhere between -Q and 2Q
(b) somewhere on the left of -Q
(c) somewhere on the right of 2Q
(d) somewhere on the right bisector of line joining -Q and 2Q
Answer:

Option (b)

39.
An electron is released from rest in an uniform electric field of 27.3 ×105 N/C. The time taken by it to attain a speed of 0.16c will be _____ . (c = 3 ×108 ms-1)
(a) 10-8 s
(b) 10-9 s
(c) 10-10 s
(d) 10-11 s
Answer:

Option (c)

40.
Electric dipole moment is a _____ .
(a) scalar quantity
(b) vector quantity
(c) tensor
(d) dimensionless quantity
Answer:

Option (b)

Showing 31 to 40 out of 141 Questions