ELECTRICAL OBJECTIVE QUESTONS AND ANSWERS --- 1

ELECTRICAL OBJECTIVE QUESTONS AND ANSWERS --- 1

DC BASICS AND NETWORKS

1.Charge on an electron is ?

a) 1.602 * 10^-19 C.         b) 1.602 * 10^-19 μC.

c) 9.107 * 10^-31 C.         d) 9.107 * 10^-25 C.

ANS: (a)

2) An electron having mass ‘m’ kg and charge ‘e’ columb travels from rest through a potential difference of ‘V’ volts. It has a kinetic energy of ?

a) mV joules                     b) m  eV joules

c) eV joules                      d) m/e  joules

ANS: (c)

AC BASICS AND NETWORKS

3) A current is said to be direct current when its ?

a) magnitude remains constant with time

b) magnitude changes with time

c) direction changes with time

d) magnitude and direction changes with time

ANS: (a)

4) A current is said to be alternating when it changes in ?

a) magnitude only                                   b) direction only

c) both magnitude and direction      d) none

ANS: (c)

DC MACHINES

5) The generator develops an electric pressure by ?

a) conversion of heat                              b) conversion of light

c) electro-magnetic induction            d) conversion of chemical energy

ANS: (c)

6) The dc generator works on the principle of ? (asked in A.M.I.E summer 1994)

a) Fleming’s left hand rule

b) Fleming’s right hand rule

c) Lenz’s law                        d) none of the above

ANS: (b)

AC MACHINES

7) The basic function of a transformer is to change ? (asked in A.M.I.E summer 1994)

a) level of the voltage               b) the power level

c) the power factor                    d)  the frequency

ANS: (a)

8) Transformer is used ?

a) to step-up the voltage           b) to step-down the voltage

c) on d.c             d) to step-up or step-down the voltage

ANS: (d)

ELECTRONICS

9) An electron device means the device in which the conduction of electrons takes place through ?

a) a gas    b) vaccum     c) a semi-conductor

d) a gas, semi-conductor or vaccum

ANS: (d)

10) Which of the following is used as a passive component in an electronic circuit ?

a) vaccum diode                 b) Zener diode

c) inductor                            d) SCR

ANS: C

POWER GENERATION

11) Which is a conventional source of energy ?

a) solar          b) radio-active substances

c) geothermal  d) wind

ANS: (b)

12) The disadvantages of renewable source of energy is/are ?

a) intermittency                 b) lack of dependability

c) availability in low energy densities   d) all the abaove

ANS: (d)

POWER SYSTEMS

13) Transmission lines connect ?

a) generating station to a switching station / step down transformer station.

b) step down transformer station to service transformer banks

c) distribution transformer to consumer premises

d) service points to consumer premises

ANS: (a)

14) A 3-phase 4-wire system is commonly used for ?

a) primary distribution                     b) secondary distribution

c) primary transmission                  d) secondary transmission

ANS: (b)

UTILIZATION OF ELECTRICAL ENERGY AND TRACTION

15 ) The basic elements of an electric drive are :

a) electric motor and the transmission system

b) electric motor ,the transmission and control system

c) the transmission and control system

d) electric motor and conversion equipment

ANS: (b)

16) The main draw back of electric drive is that:

a) it is cumbersome drive

b) it is costlier in intial as well as in maintenance cost

c) electric power supply failure makes the drive standstill

d) all of the above.

ANS: (c)

ELECTRICAL MEASUREMENTS

17) The absolute measurement of resistance involves the measurement of ?

a) length and time           b) length and mass

c) velocity                          d) either a or c

ANS : (d)

18 ) For absolute measurement of current the method commonly used is ?

a) electro-dynamometer method

b) tangent galvanometer method

c) Rayleigh current balance method

d) Lorenz method

ANS: (c)

CONTROL SYSTEMS

19) Any physical system which does not automatically correct for variation in its output, is called ?

a) open loop system

b) closed loop system

c) unstable system

d) none of the above

ANS:(a)

20) open loop control system is one in which the control action ?

a) depends on the input signal

b) is independent of the desired output

c) depends on system variables

d) depends on system size

ANS:(b)

Admin;- SAI SAIKUMAR JN (BELLAPURI SAIKUMAR)