Measurement and Instrumentation A single phase load is connected between R and Y terminals of a 415 V, symmetrical, 3-phase, 4 wire system with phase sequence RYB. A wattmeter is connected in the system as shown in figure. The power factor of the load is 0.8 lagging. The wattmeter will read + 597 W. - 597 W. - 795 W. + 795 W. + 597 W. - 597 W. - 795 W. + 795 W. ANSWER DOWNLOAD EXAMIANS APP
Measurement and Instrumentation A moving iron ammeter produces a full scale torque of 240 μNm with a deflection of 120° at a current of 10 A. The rate of change of self induction (μH/radian) of the instrument at full scale is 4.8 μH/radian. 2.0 μH/radian. 12.0 μH/radian. 114.6 μH/radian. 4.8 μH/radian. 2.0 μH/radian. 12.0 μH/radian. 114.6 μH/radian. ANSWER DOWNLOAD EXAMIANS APP
Measurement and Instrumentation A DC A-h meter is rated for 15 A, 250 V. The meter constant is 14.4 A-sec/rev. The meter constant at rated voltage may be expressed as 3750 rev/KWh. 3600 rev/KWh. 1000 rev/KWh. 960 rev/KWh. 3750 rev/KWh. 3600 rev/KWh. 1000 rev/KWh. 960 rev/KWh. ANSWER DOWNLOAD EXAMIANS APP
Measurement and Instrumentation The meter constant of a single phase 240 V induction watthour meter is 400 revolutions per KWh. The speed of the meter disc for a current of 10 Amperes of 0.8 p.f lagging will be 18.2 rpm. 16.02 rpm. 21.1 rpm. 12.8 rpm. 18.2 rpm. 16.02 rpm. 21.1 rpm. 12.8 rpm. ANSWER DOWNLOAD EXAMIANS APP
Measurement and Instrumentation In DC potentiometer measurments, a second reading is often taken after reversing the polarities of the DC supply and the unknown voltage and the average of the two reading is taken. This is with a view of eliminate the effects of Stray magnetic fields. Errorneous standardisation. Ripples of the DC supply. Stray thermal emfs. Stray magnetic fields. Errorneous standardisation. Ripples of the DC supply. Stray thermal emfs. ANSWER DOWNLOAD EXAMIANS APP