University:
Borough of Manhattan Community College
Course:
PHY 110 | General Physics
Academic year:

2024
Views:

13

Pages:

2
Author:

Anastasiya S.

Physics 110 Homework #9 (20 points) 1) Which of the following is true about electric charges? a) like charges attract, unlike charges repel * b) like charges repel, unlike charges attract c) All charges are repelled by all other charges d) All charges are attracted to all other charges Materials in which electric charges flows easily are called a) ammeters b) voltmeters c) Insulators *d) Conductors Materials in which electric charges do not flow easily are called a) ammeters b) voltmeters *c) Insulators d) Conductors Which of the following are the units for electric charge, current and potential? a) Electric charge: Amperes, Electric current: Coulombs, Electric potential: Volts b) Electric charge: Volts, Electric current: Coulombs, Electric potential: Amperes *c) Electric charge: Coulombs, Electric current: Amperes, Electric potential: Volts d) Electric charge: Amperes, Electric current: Amperes, Electric potential: Volts Electric fields are created by a) Positive charges b) Negative charges c) All objects create electric fields *d) a and b What is the direction of the electric field at point P (see diagram)? a) right *b) left c) up d) down An electrically neutral pith ball is brought near a charged rod and then allowed to touch the rod. Which of the following will happen? a) The ball will be repelled from the rod the whole time b) The ball will be attracted to the rod the whole time c) The ball will be attracted to the rod before touching but then repelled after the ball touches the rod *d) The ball will be repelled from the rod before touching but then attracted after the ball touches the rod 8) Which of the following is true about the movement of electric charges *a) Positive charges move from high voltage to low voltage. Negative charges move from low to high voltage b) Positive charges move from low voltage to high voltage. Negative charges move from high to low voltage c) Both positive and negative charges move from high to low voltage d) Both positive and negative charges move from low to high voltage According to Ohm's law, if you double the voltage, the current will be *a) Twice as large b) ½ as large c) Stay the same d) Increase and then decrease According to Ohm's law, if you double the resistance, the current will be a) Twice as large b) ½ as large *c) Stay the same d) Increase and then decrease e) Ohms Two 4x10^-6 C charges are separated by 0.2m. What will be the electric force between them? *a) 3.6N b) 3600N c) 0.72N d) 720N Show calculation F = K * (q1 * q2) markdown r^2 F = 9 x 10^9 * (4 x 10^-6)^2 markdown Копировать код (0.2)^2 = 3.6N According to Coulomb’s law, if you double the distance between two electric charges the electric force will be: a) twice as large b) Four times as large c) ½ as large *d) ¼ as large Show calculation A 20Ω resistor is connected to a 5V battery. What current will flow in the circuit? *a) 0.25A b) 4A c) 25A d) 100A Show calculation I = V / R I = 5V 20Ω = 0.25A 14) A current of 3A is measured through a light bulb when connected to a 120V outlet. What is the resistance of the light bulb? a) 0.025Ω *b) 40Ω c) 120Ω d) 360Ω 15) A current of 2A flows through a resistor of 40Ω. What is the voltage across this resistor? a) 0.05V b) 20V c) 42V *d) 80V