A single phase fully controlled converter bridge is used for electrical braking of a separately excited $$dc$$ motor. The $$dc$$ motor load is represented by an equivalent circuit as shown in the figure.

Assume that the load inductance is sufficient to ensure continuous and ripple free load current. The firing angle of the bridge for a load current of $${{\rm I}_0} = 10\,\,A$$ will be

A single $$-$$ phase, $$230$$ $$V$$, $$50$$ $$Hz$$ $$ac$$ mains fed step down transformer $$(4:1)$$ is supplying power to a half $$-$$ wave uncontrolled $$ac$$ $$-$$ $$dc$$ converter used for charging a battery ($$12$$ $$V$$ $$dc$$) with the series current limiting resistor being $$19.04\,\Omega $$. The charging current is

In the circuit of adjacent figure the diode connects the $$ac$$ source to pure inductance $$L.$$

The diode conducts for

A solar cell of $$350V$$ is feeding power to an $$ac$$ supply of $$440$$ $$V,$$ $$50$$ $$Hz$$ through a $$3$$- phase fully controlled briodge converter. A large inductance is connected in the $$dc$$ circuit to maintain the $$dc$$ current at $$20A.$$ If the solar cell resistance of $$0.5\Omega ,$$ then each thryristor will be reverse biased for a period of