Electrostatics MCQs

Question 1

The Earth's field at its surface can be calculated as if all its charge (or mass) were:

Accepted Answer

concentrated at its centre

Answer

on the North Pole

Answer

spread through space

Answer

on the equator

Question 2

An electron is accelerated from rest through a p.d. of 50 V. The kinetic energy it gains is:

Accepted Answer

8 10^-18 J

Answer

8 10^-17 J

Answer

8 10^-19 J

Answer

1.6 10^-17 J

Question 3

Workers on live high-voltage lines wear conductive suits that act as:

Accepted Answer

Faraday cages

Answer

insulators

Answer

capacitors

Answer

magnets

Question 4

Charges +Q and -Q are a distance d apart. The field at the midpoint is:

Accepted Answer

8kQd^2

Answer

2kQd^2

Answer

4kQd^2

Answer

0

Question 5

Inside a closed hollow conductor placed in an external electric field, the field is:

Accepted Answer

zero

Answer

reversed and doubled

Answer

equal to outside

Answer

stronger than outside

Question 6

An electron entering a uniform electric field at right angles to the field follows:

Accepted Answer

a parabolic path

Answer

a straight line

Answer

a spiral

Answer

a circular path

Question 7

The electric field strength due to a point charge Q at distance r is:

Accepted Answer

E = kQr^2

Answer

E = kQ^2r^2

Answer

E = kQr

Question 8

Coaxial cables have an outer braided conductor to:

Accepted Answer

shield the inner wire from external interference

Answer

carry extra current

Answer

make the cable stronger

Answer

cool the wire

Question 9

The electric field strength 0.05 m from a point charge of 4 10^-8 C in free space is:

Accepted Answer

1.44 10^5 N/C

Answer

7190 N/C

Answer

71,900 N/C

Answer

2.88 10^5 N/C

Question 10

A Faraday cage works because conductors contain:

Accepted Answer

free electrons that can move

Answer

no charges

Answer

fixed ions only

Answer

only protons

Question 11

For a point outside a charged spherical conductor, the charge can be treated as:

Accepted Answer

a point charge at the centre of the sphere

Answer

located on the nearest surface point

Answer

spread uniformly in space

Answer

zero

Question 12

The field 1 m from a point charge is 9000 N/C. The charge is:

Accepted Answer

1 10^-6 C

Answer

1 10^-5 C

Answer

2 10^-6 C

Answer

5.01 10^-7 C

Question 13

Coulomb's law is valid for:

Accepted Answer

point charges (or spherically symmetric charges)

Answer

any shape at any distance exactly

Answer

only moving charges

Answer

only magnets

Question 14

Near a sharp point on a charged conductor, the field lines are:

Accepted Answer

very close together (strong field)

Answer

parallel to the surface

Answer

absent

Answer

far apart

Question 15

A charge of 1.6 10^-19 C is placed in an electric field of 10,000 N/C. The force on it is:

Accepted Answer

1.6 10^-15 N

Answer

3.2 10^-15 N

Answer

1.6 10^-16 N

Answer

1.6 10^-14 N

Question 16

A Faraday cage is made of:

Accepted Answer

a conducting material (e.g. metal mesh)

Answer

wood

Answer

an insulator such as plastic

Answer

glass

Question 17

The SI unit of electric field strength is:

Accepted Answer

N/C (or V/m)

Answer

N

Answer

J

Answer

C

Question 18

Why is the 'point charge' model useful for spheres?

Accepted Answer

it allows Coulomb's law to be used for charged spheres

Answer

it makes the field uniform

Answer

it removes all charges

Answer

it changes the sphere's radius

Question 19

The charge on an isolated conducting sphere resides:

Accepted Answer

on its outer surface

Answer

at its centre

Answer

nowhere

Answer

uniformly through its volume

Question 20

The electric field around an isolated negative charge points:

Accepted Answer

radially inward

Answer

nowhere

Answer

radially outward

Answer

in circles

Question 21

Electric field strength is defined as:

Accepted Answer

force per unit positive charge

Answer

charge per unit force

Answer

force × charge

Answer

work per unit charge

Question 22

Two parallel plates 5 cm apart have a p.d. of 1000 V between them. The field strength between them is:

Accepted Answer

20,000 V/m

Answer

2 10^5 V/m

Answer

2000 V/m

Answer

200 V/m

Question 23

A charge of 2 10^-6 C is placed in an electric field of 5000 N/C. The force on it is:

Accepted Answer

0.01 N

Answer

0.001 N

Answer

0.02 N

Answer

0.1 N

Question 24

A positive charge released in a uniform electric field moves:

Accepted Answer

in the direction of the field, with uniform acceleration

Answer

at constant velocity

Answer

in a circle

Answer

against the field

Question 25

Cathode-ray oscilloscopes use deflecting plates to:

Accepted Answer

move the electron beam by electric fields

Answer

heat the screen

Answer

make magnetic fields

Answer

slow the electrons to rest

Electrostatics MCQs — Physics

1. The Earth's field at its surface can be calculated as if all its charge (or mass) were:

2. An electron is accelerated from rest through a p.d. of 50 V. The kinetic energy it gains is:

3. Workers on live high-voltage lines wear conductive suits that act as:

4. Charges +Q and -Q are a distance d apart. The field at the midpoint is:

5. Inside a closed hollow conductor placed in an external electric field, the field is:

6. An electron entering a uniform electric field at right angles to the field follows:

7. The electric field strength due to a point charge Q at distance r is:

8. Coaxial cables have an outer braided conductor to:

9. The electric field strength 0.05 m from a point charge of 4 10^-8 C in free space is:

10. A Faraday cage works because conductors contain:

11. For a point outside a charged spherical conductor, the charge can be treated as:

12. The field 1 m from a point charge is 9000 N/C. The charge is:

13. Coulomb's law is valid for:

14. Near a sharp point on a charged conductor, the field lines are:

15. A charge of 1.6 10^-19 C is placed in an electric field of 10,000 N/C. The force on it is:

16. A Faraday cage is made of:

17. The SI unit of electric field strength is:

18. Why is the 'point charge' model useful for spheres?

19. The charge on an isolated conducting sphere resides:

20. The electric field around an isolated negative charge points:

21. Electric field strength is defined as:

22. Two parallel plates 5 cm apart have a p.d. of 1000 V between them. The field strength between them is:

23. A charge of 2 10^-6 C is placed in an electric field of 5000 N/C. The force on it is:

24. A positive charge released in a uniform electric field moves:

25. Cathode-ray oscilloscopes use deflecting plates to:

More Physics chapters