Physics.Q3.Quiz.MARIECURIE

1.     Lila was tasked to demonstrate electrostatic charging by induction during her science class. She had a metal sphere mounted on an insulating stand, a negatively charged plastic rod, and a grounding wire. Lila held the charged rod near (but not touching) the metal sphere. She then touched the sphere with the grounding wire while keeping the charged rod nearby. Finally, she removed the grounding wire and then the charged rod. What would Lila observe after completing the process?

• The metal sphere becomes negatively charged because it directly contacted the charged rod.

• The metal sphere becomes positively charged because electrons were repelled to the ground.

• The metal sphere becomes positively charged because protons were attracted from the charged  

       rod.

• The metal sphere becomes neutral because the charges from the rod and the sphere cancel out.

Three-point charges are arranged in a triangle. Charge Q1=+2 μC is located at (0,0) charge Q2=−3 μC is at (3 m,0), and charge Q3=+4 μC is at (0,4 m). Calculate the magnitude of the net electric force on Q1. Use k=9×10⁹ Nm2/C²

                    

• 7.5 x 10^-3 N

• 5.1 x 10^-3 N

• 3.1 x 10^-3 N

• 6.2 x 10^-3 N   

Three-point charges are arranged in a triangle. Charge Q1=+2 μC is located at (0,0) charge Q2=−3 μC is at (3 m,0), and charge Q3=+4 μC is at (0,4 m). What is the distance between Q2 and Q3?

• 4m

• 5m

• 6m

• 7m

Three-point charges are arranged in a triangle. Charge Q1=+2 μC is located at (0,0) charge Q2=−3 μC is at (3 m,0), and charge Q3=+4 μC is at (0,4 m). Determine the magnitude of the net force acting on Q2

• 8.4 x 10^-4 N

• 9.2 x 10^-4 N

• 9.3 x 10^-3 N

• 8.2 x 10^-3 N

Three-point charges are arranged in a triangle. Charge Q1=+2 μC is located at (0,0) charge Q2=−3 μC is at (3 m,0), and charge Q3=+4 μC is at (0,4 m). Analyze the effect on the net force on Q1 if the value of Q2 is doubled while Q3 remain constant

 

• The net force is 7.5 x 10^-3 N

• The net force is 7.5 x 10^-6 N

• The net force did not change

• The net force decreased

Which of the following statements about electric fields is/are true?

1.     An electric field is generated by a charged particle.

2. The strength of an electric field decreases with distance from the charge.

3. An electric field only exists when charges are in motion.

• 1 and 2 only

• 1 and 3 only

• 2 and 3 only

• 1, 2, and 3

What is the net electric field on a charge?

• 2.5 x 106 N/C

• 2.8 x 106 N/C

• 5.5 x 106 N/C

• 1.2 x 107 N/C

Charges of magnitude 2 C and 5 C are located 6 meters apart in a vacuum. 10.  The direction of E due to 2 C and E due to 5 C are opposite because the electric field points are away from each other. What does this imply about the configuration of charges and the resulting electric field at the midpoint?

• The charges are like charges, and the electric field at the midpoint is zero.

• The charges are unlike charges, and the electric field at the midpoint is directed toward the        

       negative charge.

• The charges are like charges, and the net electric field at the midpoint is directed toward the

       larger charge.

• The charges are like charges, and the net electric field at the midpoint is directed away from

       the larger charge.

Three charges A(4 µC ), B(-6 µC) and C(2 µC) are placed at the vertices of a right angle triangle ABC. AC=10 cm, BC=6 cm. 10.  What is the electric force due to charges A and C?

 

• 5.2 N

• 7.2 N

• 9.2 N

• 10.2 N

Three charges A(4 µC ), B(-6 µC) and C(2 µC) are placed at the vertices of a right angle triangle ABC. AC=10 cm, BC=6 cm.  Calculate the electric force due to charges B and C.

 

• 26 N

• 28 N

• 30 N

• 32 N