Before a load is applied, the terminal (total) voltage of a power supply is measured to be 40 V. When a load of 500 N is attached the voltage across the load is measured to be 36 V. Determine the following.. 40 V R1 - 500 N 36 V (no load) a. The current when the load is a applied: mA b. The internal resistance of the power supply Ω

The lightbulb used in a computer projector has a resistance of 78 Q. What is the current through the bulb when it is operating on 120 V? A

A. Ammeter-Voltmeter Methods DATA TABLE 1 Purpose: To measure resistance values. 29.3 Voltmeter resistance R Accepted value of R DATA TABLE 2 24.6 Purpose: To measure resistance values. Rheostat Current I setting Rh ( ) Voltage V ( ) Resistance R ( ) Rheostat setting Rh Current I Voltage V R' = V/I ( ) ( ) () 1 ,011) A 1.760 1 .0117A 1.758 2 .0112 A 1.669 2 .0113 A 1.700 3 . 0106 A 1.592 3 .0107A 1.611 Average R Average R' Calculations (show work) Percent error of R Percent error of R' Ammeter resistance R 3

A 20 V battery is connected to a resistor. Neglecting the internal resistance of the battery, the power delivered to the resistor is 10 W. The resistance of this resistor is equal to a. 40 0 Ob.3.0 2 OC. 0.02 n d. 0.33 0

1. Find the current through the 1 ohm resistor in the circuit below: 1/30 www 4V 1/3Q 1/302 1/30 www 1/302 www 1/302 2. Two 6.0 μF capacitors, two 2.2 k resistors, and a 12.5 V source are connected in series. Starting from the uncharged state, how long does it take for the current to drop from its initial value to 1.30 mA?

3. What is the maximum number of 100-W light bulbs you can connect in parallel in a 120-V home circuit without tripping the 20-A circuit breaker? 4. What is the current through the 500- resistor shown? 500 £2¹ www a 400 Ω b 700 £2 ww 12.0 V

The resistors in the circuit below have the following values: R₁ = 6.80 N, R₂ = 7.00 £, and R3 = 3.10 . The two batteries each have a voltage of 3.00 v. ww R3 ww E₂ (a) Find the current in through R3. .&₁ R₁ (b) How much power do the batteries deliver to R₂? W

Two lightbulbs both operate on separate 120 V sources. One has a power of 40 W and the other is 80 W. Which of the following is true? o a. they have the same current flowing o b. the 80 w bulb has more current flowing O c. the 40 W bulb has a lower resistance o d. they have the same resistance

A battery has an emf of ε = 19 V, an internal resistance r = 28 22, and is connected to a resistor of R = 75 22. Express the current I through the circuit in terms of ε, r and R. Calculate the numerical value of I in A. Express the terminal voltage 4V of the battery in terms of I and R. Calculate the numerical value of 4V in V.

(a) What is the terminal voltage (in V) of a large 1.90 V carbon-zinc dry cell used in a physics lab to supply 1.20 A to a circuit, if the cell's internal resistance is 0.200 Q? V (b) How much electrical power (in W) does the cell produce? W (c) What power (in W) goes to its load? W