1)A 2.0-V battery is connected in a circuit with an ammeter and an unknown resistor, P. The current is observed to be 0.70 A. What would be the current in the circuit if a 12-V battery replaces the 2.0-V battery?

A)4.2 A
B)6.0 A
C)8.4 A
D)34 A

I got A

2)Which appliance consumes the most power?

A)tv. potential difference = 24 current = 0.75
B)drill. potential difference = 110 current = 1.6
C)bulb. potential difference = 12 current = 4.0
D)amplifier. potential difference = 110 current = 0.2

24^2/0.75
768

110^2/1.6
7562.5

12^2/4.0
36

110^2/0.2
60500

I got D

right on 1, but on 2) your work makes no sense.

Powerconsumed= V*I you are given v, and current for each .

on 2) i don't understand do I just multiply potential difference and current and find the largest of the bunch?

yes, you are looking for the max power.

1) B

for the second one, B is the correct answer.

1) To find the current in the circuit when a 12-V battery replaces the 2.0-V battery, you can use Ohm's Law, which states that the current (I) in a circuit is equal to the voltage (V) divided by the resistance (R). Mathematically, Ohm's Law can be written as I = V/R.

In this case, the current (I) with the 2.0-V battery is given as 0.70 A. We are asked to find the new current when a 12-V battery replaces the 2.0-V battery.

First, you need to calculate the resistance (R) of the circuit using the current (I) and the voltage (V) with the 2.0-V battery. Rearranging Ohm's Law, R = V/I. Substituting the given values, R = 2.0 V / 0.70 A.

Next, you can use the calculated resistance (R) and the new voltage (12 V) to find the new current (I). Again, using Ohm's Law, I = V/R. Substituting the values, I = 12 V / R.

To find the current, you need to substitute the calculated resistance (R) into the equation. The calculation should be I = 12 V / (2.0 V / 0.70 A). Simplifying this expression, you would get I = 12 V * (0.70 A / 2.0 V).

Calculating this expression, I = 4.2 A. Therefore, the current in the circuit when a 12-V battery replaces the 2.0-V battery would be 4.2 A.

So, the correct answer is A) 4.2 A.

2) To determine which appliance consumes the most power, you need to calculate the power (P) for each appliance. Power is defined as the product of the potential difference (V) and the current (I). Mathematically, P = V * I.

For each appliance, you can calculate the power using the given potential difference (V) and current (I), and compare the results to find the highest power consumption.

For appliance A (TV), the power can be calculated as P = 24 V * 0.75 A = 18 W.
For appliance B (drill), the power can be calculated as P = 110 V * 1.6 A = 176 W.
For appliance C (bulb), the power can be calculated as P = 12 V * 4.0 A = 48 W.
For appliance D (amplifier), the power can be calculated as P = 110 V * 0.2 A = 22 W.

Comparing the power values calculated for each appliance, you can see that the highest power consumption is for appliance B (drill) with a power of 176 W.

Therefore, the correct answer is B) drill as it consumes the most power.