Question

The brake magnet of an error free electromechanical, induction type energy meter is shifted from its position and moved a small distance towards the edge of the disc. Then the meter will

• A. continue to work correctly without any change in its characteristics
• B. continue to work, but registers a lower kWhr
• C. continue to work, but registers a higher kWhr
• D. stop working

Answer 1

The correct option is B continue to work, but registers a lower kWhr

Speed of the energy meter,
$N\propto \frac{r}{{\varphi }^{2}R}$

where,
$r\Rightarrow \text{resistance}$

$\varphi \Rightarrow \text{flux}$

$R\Rightarrow \text{radius}$

$So,ifR\uparrow ,N\downarrow$

$\therefore$ It reads a lower kWhr.