The moving coil in a dynamometer wattmeter is connected

A water boiler at home is switched on to the $$A.C$$ mains supplying power at $$230$$ $$V/50$$ $$Hz.$$ The frequency of instantaneous power consumed by the boiler is

In an oscilloscope the input to the horizontal plates is a $$100Hz$$ voltage signal. The lissajous patterns $$(A), (B)$$ and $$(C)$$ will be generated when different frequency voltage signals are applied to vertical plates. Match each lissajous pattern to the corresponding frequency by

The torque speed characteristic of a Repulsion motor resembles which of the following dc motor characteristic?