**Answer** : To measure a resistance with the help of a potentiometer it is not necessary to standardise the potentiometer.

**Answer** : For measuring a very high resistance we should use Meggar.

**Answer** : The stator of phase shifting transformer for use in conjunction with an A.C. potentiometer usually has a two-phase winding.

**Answer** : Basically a potentiometer is a device for comparing two voltages.

**Answer** : A potentiometer may be used for measurement of resistance, measurement of current, calibration of ammeter, calibration of voltmeter.

Description : When the voltage across a battery is measured using a D.C potentiometer, the reading shows 1.08 V. But when the same voltage is measured using a Permanent Magnet Moving Coil (PMMC) voltmeter, the voltmeter reading shows 0.99 ... resistance of the battery, in Ohm , is (A) 150 (B) 100 (C) 50 (D) 200

**Answer** : When the voltage across a battery is measured using a D.C potentiometer, the reading shows 1.08 V. But when the same voltage is measured using a Permanent Magnet Moving Coil (PMMC) voltmeter, ... resistance of the voltmeter is 1100 Ohm , the internal resistance of the battery, in Ohm , is 100

Description : A rheostat differs from potentiometer in the respect that it?

**Answer** : A rheostat differs from potentiometer in the respect that it has higher wattage rating.

**Answer** : In an AC. co-ordinate potentiometer, the currents in the phase and quadrature potentiometer are adjusted to be out of phase by 90°.

Description : To measure an A. C. voltage by using an A.C. potentiometer, it is desirable that the supply for the potentiometer in taken?

**Answer** : To measure an A. C. voltage by using an A.C. potentiometer, it is desirable that the supply for the potentiometer in taken from the same source as the unknown voltage.

**Answer** : In order to achieve high accuracy, the slide wire of a potentiometer should be as long as possible.

Description : We connected a 35V dc supply to a resistance of 600 Ohm in series with an unknown resistance R.A. voltmeter having a resistance of 1.2 kOhm is connected across 600 Ohm resistance and read 5v. The value of resistance R will be

**Answer** : We connected a 35V dc supply to a resistance of 600 Ohm in series with an unknown resistance R.A. voltmeter having a resistance of 1.2 kOhm is connected across 600 Ohm resistance and read 5v. The value of resistance R will be 2.4 kOhm

Description : When measuring insulation resistance of cables using d.c. source, the galvanometer used should be initially short circuited because (A) Cables have a low value of capacitance which draws a high ... high value of charging current (D) Cables have a low value of capacitance and initial resistance

**Answer** : When measuring insulation resistance of cables using d.c. source, the galvanometer used should be initially short circuited because Cables have a high value of capacitance which draws a high value of charging current

Description : State the use of shunt and series resistance used in extension of meter.

**Answer** : Use of shunt and series resistance: i) Use of shunt: To extend the range of Ammeter. ii) Use of series resistance: To extend the range of Voltmeter.

Description : When resistance element of a heater fuses and then we reconnect it after removing a portion of it, the power of the heater will?

**Answer** : When resistance element of a heater fuses and then we reconnect it after removing a portion of it, the power of the heater will increase.

Description : State the procedure for testing of earth pit resistance with necessary diagrams.

**Answer** : Following procedure (Method) for testing of earth pit resistance with necessary diagrams. 1) Earth Tester : i) Three point method ii) Four point method 2) By Potential drop method 3 ... of that earthing pit. In this test the accuracy is less but electrical rods are not required.

Description : Name two methods for measurement of low, medium and high resistance. Give one advantage and one limitation of V- I method.

**Answer** : Methods for measurement of low resistance: 1. Ammeter voltmeter method 2. Kelvin's bridge method 3. Ohm meter method 4. Potentiometer method 5. Digital/analog multi-meter ... must be infinity for perfectly accurate measurement which is not possible. 2. Connection errors.

Description : State the range for low and medium resistance.

**Answer** : Low resistances: less than 1 ohm. Medium resistances: 1 ohm to 0.1 Mega ohm.

**Answer** : Voltmeter is used to measure voltage in a circuit.Ohmmeter is used to measure the resistance of a component in a circuit.

Description : what is equivalent resistance when four 4 Ohm resistors are connected in i) series ii) parallel

**Answer** : equivalent resistance

Description : Define resistance with its unit.

**Answer** : Resistance is a measure of the degree to which a substance impedes the flow of electric current induced by a voltage. Or Resistance is the opposition to current flow in an electrical circuit. Unit is ohm.(Ω)

Description : What is the mathematical relationship between resistance and conductance?

Description : How does the resistance of a conductor compare to that of an insulator?

**Answer** : The resistance of a conductor can be significantly lower than the resistance of an insulator, depending on each material's atomic properties.

Description : Parallel Reactance and Resistance Example 1

**Answer** : Parallel Reactance and Resistance Example 1

Description : AC Circuits with Resistance but No Reactance

**Answer** : AC Circuits with Resistance but No Reactance AC Circuits with Resistance but No Reactance Series resistances let two resistances R 1 and R 2 are connected in series as shows in figure and there ... voltage. Voltage V A is common to both the branch hence voltage V A is common reference.

Description : Problems on resistance and resistivity

**Answer** : Problem on resistance and resistivity 1 : https://youtu.be/OqavD7OlZUs Problem on resistance and resistivity 2 : https://youtu.be/0eo8VO8cpwk Problem on resistance and resistivity 3 : https:// ... https://youtu.be/3neLRCTz0RQ Problem on resistance and resistivity 13 : https://youtu.be/vBCkvPOiztY

Description : Problem on temperature coefficient of resistance 3

**Answer** : Problem on temperature coefficient of resistance 3

Description : Problem on temperature coefficient of resistance 2

**Answer** : Problem on temperature coefficient of resistance 2

Description : Problem on temperature coefficient of resistance 1

**Answer** : Problem on temperature coefficient of resistance 1

Description : Problem on resistance and resistivity 13

**Answer** : Problem on resistance and resistivity 13

Description : Problem on resistance and resistivity 12

**Answer** : Problem on resistance and resistivity 12

Description : Problem on resistance and resistivity 11

**Answer** : Problem on resistance and resistivity 11

Description : Problem on resistance and resistivity 10

**Answer** : Problem on resistance and resistivity 10

Description : Problem on resistance and resistivity 9

**Answer** : Problem on resistance and resistivity 9

Description : Problem on resistance and resistivity 8

**Answer** : Problem on resistance and resistivity 8

Description : Problem on resistance and resistivity 7

**Answer** : Problem on resistance and resistivity 7

Description : Problem on resistance and resistivity 6

**Answer** : Problem on resistance and resistivity 6

Description : Problem on resistance and resistivity 5

**Answer** : Problem on resistance and resistivity 5

Description : Problem on resistance and resistivity 4

**Answer** : Problem on resistance and resistivity 4

Description : Problem on resistance and resistivity 3

**Answer** : Problem on resistance and resistivity 3

Description : Problem on resistance and resistivity 2

**Answer** : Problem on resistance and resistivity 2

Description : Problem on resistance and resistivity 1

**Answer** : Problem on resistance and resistivity 1

Description : Name the method used to measure following resistances:- (i) Low resistance (ii) Medium resistance (iii) Insulation resistance (iv) Earth resistance.

**Answer** : Following are the methods used to measure resistances:- (i) Low resistance: 1.Voltmeter-Ammeter Method 2. Kelvin's Double bridge Method (ii) Medium resistance: 1.Voltmeter-Ammeter Method 2. ... of Charge Method (iv) Earth resistance : 1. Fall of Potential Method 2. Earth tester

Description : Write any two factors on which earth resistance depends.

**Answer** : Factors on which earth resistance depends: (1) The shape and material used for the electrode (2) Depth of the electrode in the ground. (3) The specific resistance of the soil around the electrode (4) Moisture content in the soil. (5) Nature of soil

Description : Explain V- I method of measurement of medium resistance.

**Answer** : In this method, use suitable source, ammeter and voltmeter and connect them as shown in the above diagram. Take reading of voltmeter and ammeter, then value of resistance = R = V/I Ω To minimise the error take 4 to 5 observation for the same resistance and take their average.

Description : Give classification of resistance based on their ranges.

**Answer** : Classification of Resistances Based on Their Ranges: 1) Low resistance: less than 1 ohm. 2) Medium resistance: 1 ohm to 0.1 Mega ohms. 3) High resistance: greater than 0.1 Mega ohms.

Description : Define pinch off voltage and drain resistance of FET.

**Answer** : 1 . Pinch-off Voltage: It is the value of the drain to source voltage VDS at which the drain current ID reaches its constant saturation value. Any further increase in VDS does not have any ... drain to source voltage to the change in drain current. It is also called AC/dynamic drain resistance.

Description : Define the following terms as referred to battery. a) E.M.F b) Internal resistance c) Ah efficiency d) WAh efficiency

**Answer** : a) E.M.F : The electromotive force of a battery is defined as the energy spent or the work done in taking a unit positive charge around the complete circuit of the battery i.e., in ... input required to restore the initial state of charge, under specified conditions, is called Watt-hr efficiency.

Description : A resistor in which the resistance changes exponentially with change in temperature is called as A) Potentiometer B) Phototransistor C) Varactor D) Thermistor

**Answer** : A resistor in which the resistance changes exponentially with change in temperature is called as Thermistor

Description : Which of the following is the name given to resistance of thin films that are uniform in thickness? A) Area resistance B) Sheet resistance C) Filmy resistance D) None of these

**Answer** : Which of the following is the name given to resistance of thin films that are uniform in thickness? A) Area resistance B) Sheet resistance C) Filmy resistance D) None of these

Description : What is the resistance of a coil which draws 10 A and dissipates 1520 W? A) 152 Ω B) 15.2 Ω C) 1.52 Ω D) None of these

**Answer** : What is the resistance of a coil which draws 10 A and dissipates 1520 W? A) 152 Ω B) 15.2 Ω C) 1.52 Ω D) None of these

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