4) A battery with unknown emf (e) and internal resistance (r) is connected 7 puan to a circuit that involves an ideal voltmeter, a switch, and two resistors R1 =1 Q, R2 =10 Q, as shown below. When the switch is connected to a, the voltmeter reads 7 V. When the switch is connected to b, the voltmeter reads 10 V. Calculate the value of the internal resistance r. V) 31 RI R2 www

ach of the circuits below consists of identical batteries and resistors. All of the switches are closed at the same time. A F a, Rank the circuits on the basis of their total resistance. Largest 1. 2. 3. 4. 5. 6. Smallest The ranking cañnot be determined based on the information provided. b. Rank the circuits.on the basis of the elapsed time before the battery "dies". Largest 1. 2. 3. 4. 5. 6. Smallest The ranking cannot be determined based on the information provided. Explain the reasons for your rankings:

What happens to the two identical bulbs A and B con- nected to two 12V batteries, as shown, when the switch is closed? A. B. C. D. A glows, B changes A glows, B stays same A stays same, B changes A stays same, B stays same What happens when the switch is closed if I change the battery on the right to 6V? A. B. C. D. A glows, B changes A glows, B stays same A stays same, B changes A stays same, B stays same 12V 12V fmm A (mm) A B B switch switch ww 12V 6V

Consider a circuit consisting of a battery and two bulbs. Explain why the following two statements are direct consequences of the preceding definitions. A. When two bulbs are connected in series, the same current that passes through one bulb must also pass through the other. B. When two bulbs are connected in parallel, current that passes through one bulb does not pass through the other.

The current through the resistor of resistance Ra in the circuit below is: R. from left to right. V from right to left. B. V from left to right. R,+R,+R3 V from right to left. R,+R,+R,

battery (ɛ = 10V) is connected the six light bulbs (L, through L6) in the following circuit. All light bulbs have the same resistance of 10 N. After the switch K is closed, the bulbs are lit up. Which of the followings are true %3D I. L3 and L bulbs have equal brightness II. If L, and L2 bulbs burn out, no other bulb in the circuit will glow. III. The EMF source generates new electrons and supplies them to the electric circuit.

A 16.0-0 and a 20.0-0 resistor are connected in parallel. A difference in potential of 40.0 V is applied to the combination. a. Compute the equivalent resistance of the parallel circuit. b. What is the current in the circuit? C. How large is the current through the 16.0-17 resistor?