The core flux in the $$CT$$ of above problem under the given operating condition is

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

A dc A-h meter is rated for 15 A, 250V. The meter constant is 14.4 A-sec/rev. The meter constant at rated voltage may be expressed as

A moving iron ammeter produces a full scale torque of $$240$$ $$\,\mu Nm$$ with a deflection of $${120^ \circ }$$ at a current of $$10$$ $$A$$. The rate of change of self inductance $$\left( {\mu H/radian} \right)$$ of the instrument at full scale is