66.

67.

68.

69.

70.

1

72.

As per Kelvin’s Law, the most economical size of conductor is that for which :

(5) The variable part of the annual charges is equal to the cost of annual energy
108508

(0) The constant part of the annual charges is equal to the cost of energy losses per
year
(C) The variable part of the energy charges is equal to the cost of annual energy losses

(D) The constant part of the energy charges is equal to the cost of annual energy
losses

Output voltage of a simple ideal buck type de-de converter working in continuous current
mode with an input voltage of 12V and turn ON time 5ms and switching frequency 50Hz is :
வள ಗ) -6V
© उभ 10) -3V
A power electronic cireuit which can give a 2.5V, 30Hz output wave from a supply വ്‌ 5V,
60Hz supply 18 : :
(A) Voltage Source Converter (8) Cyclo converter
(C) Flyback Conveter (1) None of the above

In a power electronic circuit, a free wheeling diode is used across a de load to :
(ക Reduce output voltage ripple
(B) Prevent reversal of load voltage
)© Control output current ripple
(D) All of the above
Ten, 15V batteries each having an internal resistance of 3Q are connected in series such that
one 18 aiding the others. Its Norton’s equivalent circuit has :
(A) ക്യ source of 0.5A and parallel resistance 01 116)
(B) A current seurce of 1.1 and parallel resistance of 300
(C) A current source of 2.5A and parallel resistance of 30Q
(D) None of the above

The value of specific gravity of a lead acid battery under fully carged condition is
approximately :

@) 1.21 - (B) 2
(© 8 (D) None of the above
Which one of the following is equal to one ampere of current?
(A) Siemens/second (B) Wall/second
(0) Joule/second ` (D) Coulomb/second
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