please check these 3:

if the batteries in a portable CD player provide a terminal voltage of 12 V, what is the potential difference across the entire CD player?
a. 3.0 V
b. 4.0 V
c. 6.0 V
d. 12 V

D

two resistors having the same resistance value are wired in parallel. how does the equivalent resistance compare to the resistance value of a single resistor?
a. the equivalent resistance is twice the value of a single resistor
b. the equivalent resistance is the same as a single resistor
c. the equivalent reisstnance is half the value of a single resisstor
d. the equivalent resistance is greater than that of a single reistor

C

Which statement describes Earth's magnetic declination?
a. the angle between Earth's magnetic field and Earhts' surface
b. earht's magnetic field strength at the equator
c. the tendency for earth's field to refverse itself
d. the angle between true north and north indicated by a compass

A

yes, yes, yes

thanks!

To solve these questions, here is how you can find the answers:

1. For the first question, we need to understand that potential difference is the same as voltage. In a series circuit like the CD player, the potential difference across each component adds up to the total potential difference provided by the batteries. Therefore, the potential difference across the entire CD player will be 12 V.

So, the correct answer is option d. 12 V.

2. When two resistors are wired in parallel, the equivalent resistance is less than the resistance of a single resistor. The formula to calculate the equivalent resistance of two resistors in parallel is:

1/Requivalent = 1/R1 + 1/R2

Since both resistors have the same resistance value, we can replace R1 and R2 with the resistance value of a single resistor. It simplifies to:

1/Requivalent = 1/R + 1/R

1/Requivalent = 2/R

Requivalent = R/2

So, the equivalent resistance is half the value of a single resistor.

Therefore, the correct answer is option c. The equivalent resistance is half the value of a single resistor.

3. Earth's magnetic declination refers to the angle between Earth's magnetic field and Earth's surface. It indicates the difference between true north and magnetic north. Magnetic north is the direction that a compass needle points to.

Therefore, the correct answer is option a. The angle between Earth's magnetic field and Earth's surface.