Objective Ques - of 3EI04
Objective Ques - of 3EI04
Objective Ques - of 3EI04
(a) the lower value for a.c. voltage than for corresponding d.c. voltages (b) the same value for a.c. and
d.c. voltages(c) the higher value for a.c. voltage than for corresponding d.c. voltages (d) none of the
above
ans=d
Q14.Horizontally mounted moving iron instrument use
(a)eddy current damping (b) electromagnetic damping (c)fluid friction damping (d)air friction damping
ans=d
Q15.An astatic movement in an electrodynamometer type of instrument is used for:
(a)eliminating error on account of external magnetic fields (b) increasing the operating torque of the
instrument (c) providing eddy current damping(d) none of the above
ans=a
Q16.Avoltage of 200V at 5Hz is applied to an electrodynamometer type of instrument which is spring
controlled. The indication on the instrument is
(a)200V
(b)0V
(c)the instrument follows the variation in voltage and does not give a
study response (d) none of the above
ans=c
Q17.Electrostatic instrument are primarily is used as
(a)Ammeter
(b)Voltmeter
(c)Wattmeter
(d) ohmmeter
ans=b
Q18.An electrostatic voltmeter draws as mall value of current on d.c.
(a)under steady state condition respective of the applied voltage (b) when switched on irrespective of the
applied voltage (c)when measuring low voltage (d) when measuring high voltage
ans=a
Q19.Which meter has the highest accuracy in the prescribed limit of frequency range:
(a)PMMC (b) Moving iron (c) Electrodynamometer (d) Rectifier
ans=c
Q20.A PMMC meter rated at 50A is used in a rectifier type of instrument which uses full wave
rectification. What is the sensitivity on sinusoidal a.c.?
(a)20k /V
(b) 9k /V
(c)22.2 k /V
(d) 18 k /V
ans=d
COMPLETE 06/09/2010
Subject: Electrical Measurement(3EI04)
UNIT =2
Q1.A resistance of value 10 approximately is to be measured by ammeter voltmeter method with
resistance of 0.02 and that of voltmeter is 5000 .The resistance should be measured.
(a)by connecting the ammeter on the side of the unknown resistance as this connection gives better
accuracy
(b) by connecting the voltmeter on the side of the unknown resistance as this connection gives better
accuracy
(c)by any of the two connection ,as both of them give equal accuracy
(d) ) none of the above
ans=c
Q2.Equal resistance of 100 each are connected in each arm of a Wheatstone bridge Which is supplied
by a 2V battery source.The galvanometer of of negligible resistance is connected to the bridge can sense
as low current as 1A.The smallest value of resistance that can be measured is:
(a) 20m
(b)2
(c) 20
(d) none of the above
ans=a
Q3.A wheatstone bridge has ratio arm of 1000 and 100 resistance,the standard resistance arms
consists 4 decade resistance boxes of 1000,100,10,1 steps.The maximum and minimum value of
unknown resistance which can be determined withthis setup is
(a)111100 ,1
(b)11110 ,10
(c) 111100 ,10
(d) none of the above
ans=c
Q4.A Kelvin varley slide consists of 4 decade dividers.The first decade is constructed by having 11
coils of 10k resistance each.The subsequent will have coils of:
(a) 11 coils of 20k each, 11 coils of 40k each, 11 coils of 80k each
(b) 11 coils of 10k each, 11 coils of 5k each, 10 coils of
1k each
(c) 11 coils of 2k each, 11 coils
of 400k each, 11 coils of 80k each
(d)
11 coils of 2k each, 11 coils of 40k each, 10 coils of 80k each
ans=c
Q5.Low resistances are provided with four terminals:
(a)to facilitate the connection of current and potential circuit
(b) in order that the resistance value become definite irrespective of the nature of contacts at the
current terminal
(c) to eliminate the effect of thermoelectric emfs
(d) to eliminate the effect of leads.
ans=b
Q6.Awheatstone bridge cannot be used for precision measurement because errors introduced into on
account of
(a)resistance of connecting leads (b) thermoelectric emfs (c)contact resistance (d) All of the above
ans=d
Q7.High resistance s are provided with a guard terminal. This guard terminal is used to:
(a)By pass the leakage current
(b)guard the resistance against stray electrostatic fields
(c) guard the resistance against overloads
(d) none of the above
ans=a
Q8.Acircular piece of specimen has a surface resistance Rs. Its diameter is d and the thickness is t. The
surface resistivity s of the specimen is given by:
(a)(d2 Rs)/t
(b) (d Rs)/t
(c) (Rs t/d2)
(d) (Rs t/d)
ans=b
Q9.The value of resistance on an earthing electrode depends upon:
(a)Shape and material of the electrode
(b) depth to which electrode is driven onto earth.
(c) specific resistance of the soil
(d) all of the above
ans=d
Q10.From the point of view of safety, the resistance of earthing electrode should be:
(a)Low
(b)High
effect the safety
(c)medium
ans=a
Subject: Electrical Measurement(3EI04) UNIT =3 COMPLETE 27/09/2010
Q1.The equation under balanced conditions for a bridgeare:
R1=R2R3/R4and L1= R2R3C4
Where R1 and L1 are respectively unknown resistance and inductance.
(a) R2 and R3 should be chosen as variable(b) R2 and C4 should be chosen as variable
(c) R4 and C4 should be chosen as variable
(d) R3 and C4 should be chosen as variable
ans=c
Q2.Maxwells Inductance-capacitance bridge is used for measurement of inductance of:
(a) Low QCoil
(b) Medium Q Coil
(c) High Q Coil (d) Low and Medium Q Coil
ans=b
Q3.The advantage of Hays bridge over the Maxwells Inductance-capacitance bridge is because
(a) its equation for balance donot contain any frequency term (b) it can be used for measurement of
inductance of high Q coils (c) it can be used for measurement of inductance of Low Q coils
(d)none of the above
ans=b
Q4.In DSautys bridge(unmodified form) it is:
(a) it is possible to obtain balance even if both the capacitor are imperfect (b) it is possible to obtain
balance if one of the capacitor are perfect
(c) it is possible to obtain balance only if both the capacitor are perfect (d) All of the above
ans=c
Q5.Frequency can be measured by using
(a) Maxwells bridge (b) Schering Bridge (c) Heaviside Campbell bridge
ans=d
Q6.Abridge circuit works at a frequency of 2kHz. The following can be used as detector for detection
of null condition in the bridge
(a) Vibration galvanometer and head phone (b) head phone and tunable amplifier
(c) Vibration galvanometer and tunable amplifier (d) Vibration
galvanometer and head phone and tunable amplifier
ans=b
Q7.Wagners Earth devices are used in a.c. bridge circuit for
(a) Eliminating the effect of earth resistances
(b) Eliminating the effect of inter-component capacitance
(c) Eliminating the effect of stray electrostatic field
(d) shielding the bridge element
ans=a
Q8.The value of Q-factor for Hays bridge is between
(a)Q>10 (b)Q=10 (c) Q<10 (d) 1<Q<10
ans=a
Q9. The value of Q-factor for Hays bridge is given as
(a) Q= L1R1
(b) Q= L1/R1 (c) Q=/ L1R1 (d) none
ans=b
(c)
f=
1
2 R1 R 2