PHYS 150 | Exam 2 Questions and Answers with 100% Correct Answers |
Latest Version Already Graded A+
Which of the following is true of electric charges
(positive and negative)? - (ANSWER)Like charges repel
Chemical reactions produce voltages that are
typically - (ANSWER)1 volt = 1 eV per electron
When you get an electric shock from a door knob,
the voltage is typically - (ANSWER). 10,000 volts - actually, more like 50,000 volts;
- Sparks - 30,000 volts/cm (in air)
- A spark is an electric current in air
An electric spark of 50,000 volts may not hurt you if - (ANSWER)A. the current is low
B. the current lasts a very short time
C. the power is low
- P = IV
- Energy = P x time
The voltage from an electrical outlet is - (ANSWER)C. varying (average 120 volts); - Varies 60 times/sec
(60 Hz)
- Alternating current (AC) vs Direct current (DC)
The current through a 10 W LED bulb is about - (ANSWER)0.1 Amps; P = IV
10 W = I x 110 Volts; I = 0.1 Amps
, PHYS 150 | Exam 2 Questions and Answers with 100% Correct Answers |
Latest Version Already Graded A+
We use AC for electric power distribution because - (ANSWER)A. it makes it easy to change voltage; -
High voltage -> Low current (P=IV)
- Low current -> Less power loss to heat (I2R)
A step-up transformer increases the voltage and - (ANSWER)decreases the current
Which of the following is a difference between
electric charges and magnetic poles? - (ANSWER)Poles do not exist in isolation
Magnetism is created by - (ANSWER)electric currents; - Permanent magnet: spinning electrons
- Electromagnet: electric current
The Earth's magnetic field is produced by - (ANSWER). electric currents in the outer core; - Liquid outer
core of
molten iron and nickel
- Inner core is solid
iron-nickel
The Earth's magnetic field flips - (ANSWER)about once every million years
The charge of a particle - (ANSWER)must be an exact multiple of the charge of a quark.
In a permanent magnet, the magnetism comes from: - (ANSWER)the spin of the electrons.
The Earth's magnetism comes from - (ANSWER)a dynamo in the core.
The north geographic pole of the Earth - (ANSWER)is a south magnetic pole.
Latest Version Already Graded A+
Which of the following is true of electric charges
(positive and negative)? - (ANSWER)Like charges repel
Chemical reactions produce voltages that are
typically - (ANSWER)1 volt = 1 eV per electron
When you get an electric shock from a door knob,
the voltage is typically - (ANSWER). 10,000 volts - actually, more like 50,000 volts;
- Sparks - 30,000 volts/cm (in air)
- A spark is an electric current in air
An electric spark of 50,000 volts may not hurt you if - (ANSWER)A. the current is low
B. the current lasts a very short time
C. the power is low
- P = IV
- Energy = P x time
The voltage from an electrical outlet is - (ANSWER)C. varying (average 120 volts); - Varies 60 times/sec
(60 Hz)
- Alternating current (AC) vs Direct current (DC)
The current through a 10 W LED bulb is about - (ANSWER)0.1 Amps; P = IV
10 W = I x 110 Volts; I = 0.1 Amps
, PHYS 150 | Exam 2 Questions and Answers with 100% Correct Answers |
Latest Version Already Graded A+
We use AC for electric power distribution because - (ANSWER)A. it makes it easy to change voltage; -
High voltage -> Low current (P=IV)
- Low current -> Less power loss to heat (I2R)
A step-up transformer increases the voltage and - (ANSWER)decreases the current
Which of the following is a difference between
electric charges and magnetic poles? - (ANSWER)Poles do not exist in isolation
Magnetism is created by - (ANSWER)electric currents; - Permanent magnet: spinning electrons
- Electromagnet: electric current
The Earth's magnetic field is produced by - (ANSWER). electric currents in the outer core; - Liquid outer
core of
molten iron and nickel
- Inner core is solid
iron-nickel
The Earth's magnetic field flips - (ANSWER)about once every million years
The charge of a particle - (ANSWER)must be an exact multiple of the charge of a quark.
In a permanent magnet, the magnetism comes from: - (ANSWER)the spin of the electrons.
The Earth's magnetism comes from - (ANSWER)a dynamo in the core.
The north geographic pole of the Earth - (ANSWER)is a south magnetic pole.
