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The ratio of voltage and electric current in a closed circuit
(a) remains constant (b) varies (c) increases (d) falls
The resistance of a wire varies inversely as
(a) area of cross section (b) length (c) resistivity (d) temperature
The electrical conductivity of metals is typically of the order of ( in ohm-1 m-1)
(a) 10 to the power of 7 (b) 10 to the power of 5 (c) 10 to the power of -4 (d) 10 to the power of -6
Four resistors, each of resistance R ohms are available. The minimum resistance of the combination will be
(a) 4R (b) R (c) R/4 (d) R/8
The elements which are not capable of delivering energy by its own are known as
(a) unilateral elements (b) non-linear elements (c) passive elements (d) active elements
The magentic susceptibility of paramagnetic material is
(a) less than zero (b) less than one but positive (c) greater than one (d) equal to zero
The Direction of current in an ac circuit
(a) is from positive to negative (b) is always in one direction (c) varies from instant to instant (d)Cannot be determined
which of the following statements associated with purely resistive circuits is correct?
(a) PF is unity (b) Power consumed is zero (c) Heat produced is zero (d) PF is zero
The magnetic field energy in an inductor changes from maximum value to minimum value in in 5m sec when connected to an ac source. The frequency of the source is
(a) 20 Hz (b) 50 Hz (c) 200 Hz (d) 500 Hz



Control Systems:

Electronic control systems have the serious draw-backs of
(a) low reliability (b) operational difficulty (c) temperature sensitiveness (d) all of above
The system whose characteristic equation has the following roots is marginally stable
(a) -j, j, -1,1 (b) -3,-2,0 (c) -2+3j, -2-3j, -2 (d) -3,-2,-1
A phase log compensation will
(a) improve relative stability
(b)increase the speed of response
(c)increase band-width
(d) increase overshoot
For Nyquist plot we use

open loop function
closed loop function
characteristic equation
any of the above

A system with gain margin close to unity or a phase margin close to zero is

highly stable
oscillatory
relatively stable
none of these

Root locus diagram exhibits the

frequency response of a system
poles of the transfer function for a set of parameter values
bandwidth of system
all of the above

Increase in the gain K makes the system

more stable
unstable
none of above

The transfer function of a system is used to determine

the output for a given input
the type of system
the input for a given output
the steady state gain

In a servo system the voltage induced in the control transformer rotor is the

error voltage
driving voltage
opposing voltage
none of these

With the feedback system, the transient response

decays slowly
decays rapidly
rises slowly
rises quickly



Measurements and Instrumentation

Which of the following types of instrument is an integrating instrument?

power factor meter
energy meter
wattmeter
frequent meter

Which of the material is used for the ’swamping’ resistance that is connected in series with the working coil of a voltmeter?

Constantan
Manganin
Eureka
Nichrome

What are used to increase the range of ammeters.

Multipliers
Shunts
Control Springs
Potential transformers

Which voltmeter do you select for measuring 50KV DC?

Moving Coil Voltmeter
Hot wire voltmeter
Electro Dynamo meter
Electrostatic Voltmeter

Which of the following you will prefer to extend the range of an ac voltmeter?

Low series resistance
high resistance in parallel
CT
PT

High AC voltages are usually measured with

magnetic voltmeter
inductive voltmeter
potential transformers with voltmeters
current transformers and voltmeters

Creeping is the phenomena occurs in

voltmeter
wattmeter
energy meter
ammeter