Trade Theory Semester 1 January 2018

Anand Tue, 01/04/2022 - 11:58

Choose the correct answer:
1. The forbidden energy gap for germanium is -
a) 0.3 eV
b) 3.5 e
c) 0.72 eV
d) 1.1 eV
2. The bandgap of silicon at room temperature is -
a)1.3 eV
b) 0.7 eV

c)1.1 eV
d) 1.4 eV
3. The earth wirs are made of -
a) Copper
b) Aluminium
c) Iron
d) Galvanized stranded stee

4. The rating of fuse is always expressed in -
a) Volts
b) Amperes
c) Ampere-volts
d) Ampere hours

5. A fuse is -
a) Always connected in series with the circuit
b) Always connected in parallel with the circuit
c) Normally connected in series with the circuit
d) Normally connected in parallel with the circuit

6. The size of conductor used in power cables depends on -
a) Operating voltage
b) Power factor

c) Current to be carried

d) Type of insulation used

7. Ohm's law is applied to -
a) Semiconductors
b) Electrolytes
c) Carbon resistors
d) All of these

8. Two wires A and B of the same material and length L and 2L have radius R and 2R
respectively. The ratio of their specific resistance will be -
a) 1:a
b) 1:2
c) 1:4
d) 1:8

9. Ideal voltage sources have -
a) Zero internal resistance
b) infinite internal resistance
c) Low value of current
d) Large value of emf

10. Kirchhoff's laws are valid for-
a) Linear circuit only
b) Passive time invariant circuits
c) Nonlinear circuits only
d) Both linear and nonlinear circuits

11.The unit of impedance is -
a) Ohms
b) Siemens
c) Mho
d) Henry

12. The value of peak factor of a sinusoidal waveform is-
a) Zero
b) 1
c) 1.11
d) 1.41

13. The algebraic sum of incoming current is equal to the sum of outgoing current is the-
statément of
a) Kirchoff's current law
b) Kirchoff s voltage law
c) Ohm' s law
d) Joule's law

14. A 12 V battery under fully charged condition has open circuit voltage of-
a) 12 V
b) < 12 V
c) > 12 V
d) ≤ 12 V

15. A 100W, 220 volt lamps takes a current of -
a) 5/11 A
b) 2.2 A
c) 022 A
d) 5/22 A

16. The r.m.s. value of sinusoidal alternating current is given by the relation-
a) Im/2
b) 0.637 Im
c) 2Im/π
d) Im√2

17. In a pure inductive A.C. circuit -
a) Voltage leads the current vector by 90⁰
b) Voltage legs the current vector by 90⁰
c) Current leads the volage vector by 90⁰
d) Current is in phase with the voltage vector

18. Primary battery is such a battery -
a) Which can be recharged
b) Which cannot be reconditioned by replacing chemical
c) Which cannot be reused
d) Which cannot be recharged

19. Internal resistance of a battery cell increases with -
a) Increases in concentration of electrolyte
b) Increase in distance between two electrodes
c) Increases in area of the plates inside the electrolyte
d) Increase in size of the electrodes

20. If cells are connected in series, then ________________ will increase.
a) Current
b) Voltage

c) Power
d) Energy

21. If Z is the electro - Chemical equivalent of a substance of the electrolyte. E is the
chemical equivalent of the same substance, then the relation between Z & E will be -
a) Z ∝ E
b) Z = E
c) Z < E
d) Z > E

22. Negative electrode or anode of simple voltaic cell is made of-
a) Copper
b) Zine
c) Lead
d) Carbon

23. E.C.E stands for -
a) Electrovalent chemical equivalent
b) Electrolysis cathode equivalent
c) Electro chemical equivalent

d) None of these

24. Resistivity of metals is expressed in terms of-
a) μΩ
b) μΩ -cm /° C
c) μΩ - cm
d) Ω

25.Permittivity of free space is equal to -
a) 8.84 x 10^-12F/m
b) 8.84 x 10^-13F/m
c) 8.84 x 10^-11F/m
d) 8.84 x 10^-10F/m

26.Which resistor will be physically larger in size?
a) 100 Ω , 10 W
b) 10 Ω, 50 W
c) 1 MΩ , 1/2W
d) 1 kΩ, 1 W

27.Two resistor are said to be connected in parallel when-
a) Same current passes in turn through both
b) Both carry the same value of current
c) Voltage across each resistance are same
d) Voltage across each resistance are not same

28.The electrical resistance of human body is around-
a) 5 ohms
d) 25 ohms
c) 250 ohms
a) 1000 ohms

29. A 3Ω resistor having 2A current will dissipate the power of –
a) 2 W
b) 4 W
c) 8 W
d) 12 W

30. The filament of an electric bulb is made of –
a) Carbon
b) Nickel
c) Aluminium
d) Tungsten

31. An current of 6 A is same as
a) 6 Joule / Secondb

b) 6 Coulomb/ Second
c) 6 Watt/Second

d) None of these

32. The equation of alternating current is i=42.4 sin 628 t. Then the average value of current

a) 42.42 A
b) 27 A
c) 38 A
d) 22 A

33. The rms value of a half wave rectified symmetrical square wave current of 2 A is given
by -
a) 0.707 A
b) I A
c) 1.414 A
d) 1.732 A

34. A capacitor stores 0.24 coulombs at 10 volts. Its capacitance is:
a) 0.024 F
b) 0.12 F
c) 0.60 F
d) 0.80 F

35. If the sheet of a backelite is inserted between the plates of an air capacitor, the
capacitance will-
a) Decrease
b) Increase
c) Becomes zero
d) Remains unchanged

36. Three capacitors each of capacity C are given. The resultant capacity (2/3) C can
obtained by using them-
a) All in series
b) All in parallel
c) Two in parallel and third in series with this combination
d) Two in series and third in parallel across this combination

37. The power dissipated in a pure capacitor is-
a) Zero
b) Proportional to applied voltage
c) Proportional to the value of capacitance

d) Both (b) & (c)

38. Three element having conductance G₁, G₂ and G₃ are connected in parallel. Their
combined conductance will be -
a) (G₁ + G₂ + G₃)^-1
b) G₁ + G₂ + G3
C) 1/G₁+1/G2₂+ 1/G₃
d) (1/G₁, + 1/G₂ + 1/G₃)^-1