Phy213: General Physics III 1/14/2019Chapter 27 Worksheet 1Internal Resistance1. A real battery has a potential difference of 12V when no load is attached. A 20  load circuit is then attached to the battery, drawing 5 W of power.a. What is the current that flows through theload circuit? b. What is the potential difference across theload circuit?c. What is the internal resistance of the battery?Ohm’s Law & Electrical Circuits:2. Consider the following circuit:a. What is the equivalent resistanceof this circuit?b. How much total current is drawnfrom the battery?c. How much total power is drawn from the power source? d. If the circuit is connected for 10 minutes, how much energy is drawn from the battery? e. How much charge? f. How many electrons?5 10 5 +-10 10 10 10 V+-Rload=20 12VPhy213: General Physics III 1/14/2019Chapter 27 Worksheet 23. Consider the following circuit:a. What is the equivalent resistance of this circuit?b. How much total current is drawn from the battery?c. How much current is flowing through each resistor? d. How much power is dissipated across resistor R? 4. Consider the following circuit:a. What is the current through the 20  resistor?b. What is the current through the 10  resistor?20 10 10 V+ -+ -5 V+-10 R = 10 5 10 20 V20 Phy213: General Physics III 1/14/2019Chapter 27 Worksheet 35. A “Wheatstone Bridge” circuit is shown in the following diagram. The voltage from the top terminal to the bottom terminal is 120 V and the resistor values are:R1=20  R2=??R3=50  R4=40 R5=10 a. Determine the value of R2 when the current through R5 is zero, (iR5= 0 A).b. What is the equivalent resistance for this circuit?c. What is the current through R2?d. Calculate the rate of resistive heat loss (power) through R2.e. Determine the value of R2 when the current through R5 is zero, iR5= 0.1 A.6. Consider the following RC circuit.a) What is the equivalent capacitance for this circuit?b) What is the RC time constant for this circuit? c) What is the significance of this RC constant?d) If the battery is removed from the circuit and the capacitors are allowed to discharge, how long would it take for the charge in the capacitor to be 20% of the fully charged value?e) What would be the potential difference across the discharged capacitor in (d)?+-20 F1000 10 V10 F15 FR4R3+-R2R5R1iR5Phy213: General Physics III 1/14/2019Chapter 27 Worksheet 47. The Hodgkin-Huxley model of the giant squid axon surface membrane is illustrated below. In this model, you will consider 2 independent and exclusive ion pathways, Na+ and K+, respectively. The ions can only flow through their corresponding pathway. The resting (equilibrium) membrane potential (V=Vinside-Voutside) is -65 mV and the conductance per unit area of the K+ pathway is 50 m-1/cm2.a. What is the direction of Na+ and K+ ion flow, respectively?b. What is the net current density across the surface membrane at equilibrium?c. What is the K+ current density?d. What is the Na+ current density?e. Determine the conductance per unit area for the Na+ pathway.f. Determine the resistance per unit area for each ion, RNa/A and RK/A.g. What is the charge density of the surface membrane? Hint: Treat the surface membrane as acapacitor, where the capacitance per unit surface area is 0.01 F/m2.InsideOutsideRKVNa=67mVRNa-++-VK=98mVCMPhy213: General Physics III 1/14/2019Chapter 27 Worksheet 5Application: The Low Pass Filter8. A simple filter circuit can be constructed from a resistor in series with a capacitor. An input voltage source is connected to the left side terminals and a “load circuit” is connected to the output terminals. An advantage of this circuit design is that it can resist current spikes associated with unexpected, rapid voltage jumps, which would otherwise damage the load circuit.a. What is the ratio of the input to outputvoltage, in terms of the filterresistance R and Rload?b. What is the necessary DC inputvoltage to achieve a desired outputvoltage of 10 V? Assume that R is 550 and Rload is 50 .c. When the filter capacitor is completelycharged, how much current flows intothe load circuit?d. For a voltage spike that linearly increases the input voltage by 1000V over a time of 0.001 s, what is the final voltage across the filter capacitor (0.5 F) at the top of the voltage spike?d. What is the peak current flow into the capacitor?e. What is the peak current flow into the load