PH03_Resistivity

Electrical instrumentation question on Wheatstone bridge:

1. What diodes are forward biased? a. D1 b. D2 c. Both 2. The only open circuit is a. R1 side b. R2 side c. Everything is closed d. D2 side 3. R1 and R2 are parallel a. True b. False c. Not applicable

What minimum value of series resistance is required when three 10-watt, 10-volt, 1000-mA zener diodes are connected in series to obtain a 30-volt regulated output from a 45 volt d.c. power source ? R E₁-45 V Eo=30 V ļ O 30 ohm O 15 ohm O 35 ohm O 550hm

What minimum value of series resistance is required when three 10-watt, 10-volt, 1000-mA zener diodes are connected in series to obtain a 30-volt regulated output from a 45 volt d.c. power source? R E₁-45 V Eq=30 V 30 ohm O 15 ohm 35 ohm O 55ohm

What minimum value of series resistance is * required when three 10-watt, 10-volt, 1000- mA zener diodes are connected in series to obtain a 30-volt regulated output from a 45 volt d.c. power source? R www E₁-45 V Eo= 30 V 30 ohm O 15 ohm O 35 ohm 55ohm

For the network shown in Figure B22 , assume E = 18V, Diode D¡ as silicon and D2 Germanium, R1=3KQ and R2=2K2. Calculate, i. Current I,, ii. Current In2 ii. Voltage across resistor R2 R1 D E D2 R2 Figure B22 +

1- Some copper wire has a resistance of 200 at 20°C. A current is passed through the wire and the temperature rises to 90°C. Determine the resistance of the wire at 90°C, correct to the nearest ohm, assuming that the temperature coefficient of resistance is 0.004/°C at 0°C

During the Wheatstone Bridge experiment, when the pointer is at the balance point then: O a. The potential difference across the unknown resistance is equal to the potential difference between the end of the wire connected to the known resistance.the balance point. O b. The potential difference across the known resistance is equal to the potential difference between the balance point and the point of contact between the known andunknown resistances. O c. The potential difference across the unknown resistance is equal to the potential difference across known resistance. O d. The potential difference across the unknown resistance is equal to the potential difference between the balance point and the end of the wire connected to the unknown resistance. O e. The potential difference across the unknown resistance is equal to the potential difference between the balance point and the end of the wire connected to the known resistance. Clear my choice

For the circuit shown in figure 1, the diodes is in complete model and the resistance of both diodes are 5 Ohm. Find the current in the resistance RL. When the both switch S1 and switch S2 are ON. v1= 6V, V3 =3 Vv2=12 V.

1. Given a typical tungsten filament of a light bulb, 1 m long and 0.05mm in radius. nim B. Given that the temperature resistivity coefficient of tungsten is 4.5 X 10-3/ °C, meldoig zinovovd omo A. Calculate the typical resistance of the filament given that its resistivity at 20 °C is 5.6 X 10-8 (Q -m). calculate the resistance at 2000 °C. assuming linear resistivity-temperature 2000 ert pria relation.

30. A wooden board of 30cm X15cm X 2cm is to be heated from 30°C to 180°C in 10 minutes by dielectric heating using 40MHZ supply. Specific heat of wood is 0.35 and density 0.55gm/ccm, relative permeability = 5 and power factor = 0.05. Estimate the voltage across specimen and current during heating. Assume efficiency as 90%.

Please help me with my pre-lab activity number 3, I'm having trouble

A two wires, one of Copper and the other of Nickel, if the resistance of the first is (12.7 Q), and the second is (11.6 0) at room temperature, at what temperature are their resistances equal? Note that the temperature coefficient of resistivity of Copper is (0.0039 C-1), and for Nickel it is equal to (0.006 C1).

Problem 13. Some copper wire has a resistance of 200 2 at 20°C. A current is passed through the wire and the temperature rises to 90°C. Determine the resistance of the wire at 90°C, correct to the nearest ohm, assuming that the temperature coefficient of resistance is 0.004/°C at 0°C.

I need answer within 20 minutes please please with my best wishes

A PMMC type meter has a full scale deflection of 10 mA. The resistance of the coil is 30 ohm. Then (1) shunt value for an Ameter of 50 A range and (2) Find the value of series resistance required for the range up to 500 V.

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10) A certain batch of copper wire was found to have a conductivity of 98% at 20°C. What is its resistivity in un-cm? 11) The resistance of a copper at 30°C is 500. If the temperature coefficient of copper at 0°C is 0.00427. What is the resistance at 100°C?

8. The resistance of a copper at 30°C is 50 ohms. If the temperature coefficient of copper at 0°C is 0.00427. What is the resistance at 100°C? 9. A wire has a resistance R are cut into 2 pieces and the small pieces are connect in parallel resulting to a total resistance of 2 ohms. What is the value of R?

What minimum value of series resistance is required when three 10-watt, 10-volt, 1000-mA zener diodes are connected in series to obtain a 30-volt regulated output from a 45 volt d.c. power source ? R w E₁-45 V Eo= 30 V ↓

Question 3 a. Some materials exhibit the property of superconductivity under certain conditions. State what is meant by superconductivity and explain the required conditions for the material to become superconducting. b. The diagram below shows the cross-section of a cable consisting of parallel filaments that can be made superconducting, embedded in a cylinder of copper. copper cylinder filament The cross-sectional area of the copper in the cable is 2.28 x 10-7 m². The resistance of the copper in a 1.0 m length of the cable is 0.075 N. Calculate the resistivity of the copper, stating an appropriate unit. State and explain the what happen to the resistance of the cable when the embedded filaments of wire are made superconductive? i.

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The resistance of wire increases from 40 – ohm at 20 0C to 50 – ohm at 70 0C. Find the temperature coefficient of resistance at 0 0C.

What is the resistance of a copper specimen with an initial resistance of 250 ohms at 30 degrees Celsius? Present temperature is 48 degrees Celsius and RTC at 0 degree Celsius of 1/231.9 per degree Celsius?

Notes on the verification of ohm's law by voltage method?

45. Equivalent electrical parameter of MMF in electric circuits. a.   Voltage b.   Resistance c.   Current d.   Conductance

QUESTION 7 Match Collumn A and Collumn B? Properties of Metal v Britleness A. the property of a metal which allows little bending or deformation without shattering Conductivity B. the property of metal to resist deformation and stress without breaking the property of a metal which can be hammered, rolled. or pressed into various shape without C. v Hardness cracking, breaking or leaving some other detrimental effect v Strength D. the property of a metal to resist cutting, penetration and abbrasion v Elasticity E. the weight of a unit volume of a material F. the property of a metal to become liquid by the application of heat v Malleability the property of metal which enables a material to return to its original state when the force G. applied is removed v Fusibility v Density H. the property of a metal to conduct electricity or heat Click Save and Submit to save and submit. Click Save All Answers to save all answers. Beno

Breakdown strength of the gases experiment the current will be increased by a. Cathode produced electrons b. Anode attraction c. Free electrons d. Additional electrons

A. Using long coupon bond(s), make a written discussion of what you learned in this lesson. Your discussion includes but not limited to the following: 1. Electric current, direct and alternating current, average current 2. Emf, dependent and independent sources 3. Conductance and conductivity 4. Resistance and resistivity 5. Percent conductivity 6. D-c measurements of voltage, current, resistance B. Calculate the resistivity and percent conductivity of the elements and alloys listec in the table below. 1. Resistivity Elements Ohm-cm Ohm-meter Alloys Ohm-cm Ohm-meter Brass Silver German silver Copper, Manganin Copper, Lucero Gold, pure Advance Aluminum Constantan Magnesium Excello Tungsten Nichrome Zinc Nichrome II Nickel Chromel Iron, cast Platinum Iron, Lead

For the network shown in Figure B22 , assume E- 12V, Diode D, as silicon and D: Germanium, Ri=1.5KQ and R2=IKN. Calculate, i. Current I. Current Ioz. ii. Voltage across resistor R: R1 D E ZD2