Electrostatic Quizzes

Two point charges +35μC and Q are placed 300cm apart. If they attract each other with a force of 0.525N, what is the charge of Q?

• +167 μC

• +15 μC

• -15 μC

• -167 μC

Two point charges attract each other with force, F. If one of the charges is tripled and the separations between the charges is reduced to one quarter of its original distance, the new force is

• 3/4 F

• 9/16 F

• 12 F

• 48 F

The electric field strength is the

• work done to bring a proton at a point

• electrostatic force that acts on a proton placed at a point

• electrostatic force that acts on a unit of positive charge at a point

• work done to bring a unit of positive charge from infinity to a point

A dust particle of mass 2.0 x 10^-18 kg carries a charge of -1.60 x 10^-19 C.

It is placed in a uniform downward electric field strength of 200 NC^-1 and a uniform gravitational field strength of 9.81 Nkg^-1. What is the magnitude and direction of the resultant force of the dust particle?

• 1.24 x 10^-17 N

  (upwards)

• 1.24 x 10^-17 N

  (downwards)

• 5.16 x 10^-17 N

  (upwards)

• 5.16 x 10^-17 N

  (upwards)

A spherical surface of radius R containing charges +2Q, -3Q, and +5Q is shown in the diagram.

What is the total electric flux which passes through the spherical surface?

Which diagram shows the correct electric field lines when a spherical conductor is placed in a uniform electric field?

• 
• 
• 
• 

A conductor with thickness t is inserted in the centre between two charged metal plates as shown in the diagram.

Which statement below is true about the conductor if the potential difference across the plates is V ?

• The electric field strength inside the conductor is equal to zero.

• The electric field strength inside the conductor is greater than outside the conductor.

• The electric field strength between the plates remains unchanged.

Three positive point charges each of magnitude Q are placed one after another at each corner of equilateral triangle of side a. What is the total potential energy of the system of charges?

The work done to bring a positive charge of 1.6 x 10^-19 C from infinity to a point P in an electric field is 8.0 x 10^-16 J.

What is the electric potential at P ?

• - 5.0 x 10³ V

• - 2.5 x 10³ V

• 2.5 x 10³ V

• 5.0 x 10³ V

Two point charges P and Q are separated by a distance of 1.8 x 10^-12 m as shown in the diagram.

• 2.0 x 10⁶ J

• 1.6 x 10¹¹ J

• 2.3 x 10¹² J

• 5.0 x 10¹²J