Induction Type Instruments & Energy Measurement - Multiple Choice Questions and Answers

Induction Type Instruments & Energy Measurement - Multiple Choice Questions and Answers Points : Induction Type Instruments & Energy Measurement, MCQS, Objective type question, Multiple choice questions and answer 1. The deflecting torque in shaded-pole induction ammeter is proportional to...
(a) Current
(b) Square of current
(c) Square of voltage
(d) Both (b) & (c)

2. Damping torque in the case of shaded-pole induction ammeter is produced by...
(a) Eddy current
(b) Permanent magnet
(c) Both (a) & (b)
(d) Balance weight

Advantage and Disadvantage of Merz Price Demand Indictor

Advantage and Disadvantage of Merz Price Demand Indictor Points : Advantage and Disadvantage of Merz Price Demand Indictor Advantage The advantage of this type of indicator is that indication increases at the constant rate for a constant load. Its scale is, therefore, uniform and is calibrated down to zero. It is more accurate.

Construction of Merz Price Demand Indictor

Construction of Merz Price Demand Indictor Points : Construction of Merz Price Demand Indictor This indicator is not in the form of a separate unit, but it is an attachment which can be used with any type of motor or clock-meter and it based on the fact that it the energy flowing in a circuit is measured, say, in watt- hours, for a series of time intervals of equal duration, then the individual blocks of energy measured are themselves equal to the average power consumed. This follows from the relation.

Applications of Wright Maximum Demand Indicator

Applications of Wright Maximum Demand Indicator Points : Applications of Wright Maximum Demand Indicator It can be conveniently used, due to its low cost, in an ordinary house service installation for assessing the maximum demand.

Advantages: and Disadvantages of Wright Maximum Demand Indicator

Advantages: and Disadvantages of Wright Maximum Demand Indicator Points : Advantages: and Disadvantages of Wright Maximum Demand Indicator Advantages (i) The instrument is suitable for both d.c. and a.c. circuits.
(ii) It is robust and cheaper than the Merz-price type and can he made to withstand heavy momentary overloads.

Construction of Wright Maximum Demand Indicator

Construction of Wright Maximum Demand Indicator Points : Construction of Wright Maximum Demand Indicator Such an instrument consists of a glass U-tube having two bulbs of similar capacity at their upper ends as shown. The glass bulb on the left side of the tube consists of a metallic strip around it, which being connected in series with the load circuit, carries the load current, thus it forms a heater and heats the air inside this bulb. Just below the bulb on right side of the tube, there is a side tube leading to a narrow bore index tube fitted with a scale along it. The glass U-tube contains a liquid of low temperature co-efficient of expansion; dilute sulphuric acid as an indicator. The constructions and traps in the limbs of the tube are to prevent the passage of air from one bulb to the other.

Maximum Demand Indicator

Maximum Demand Indicator Points : Maximum Demand Indicator, Wright Maximum Demand Indicator, Merz-Price Demand Indicator Since an electrical supply company must be ready to supply energy at whatever rate is needed, to meet the operating requirements of its consumers, generating and distribution equipment must be installed to provide for the maximum demand for electrical energy, rather than merely the average demand. The additional capacity installed, in order to take care of this maximum demand, involves an investment which would give return only for a portion of the time unless proper allow an were made for it in setting up rate schedules.

Range of Tests of Single Phase Induction Type Energy Meter

Range of Tests of Single Phase Induction Type Energy Meter Points : Range of Tests of Single Phase Induction Type Energy Meter A typical scheme of tests for an a.c. energy meter would consists of tests
(a) At the lowest current at which the accuracy is guaranteed (usually 5% of basic current)
(b) AT one intermediate current.