BSNL TTA EXAM MODEL QUESTIONS ON BASIC ELECTRICAL

Q. The specific resistance of a wire depends on:-

    (a) Nature of the material   (b) length

    (c) Cross-sectional area      (d) dimension.

Ans: - (a)

 Q. The electric current is due to the flow of

  (a) Positive charge only

  (b) Negative charge only

  (c) Both positive and negative charge

  (d) Neutral particles only

Ans: - (c)

Q. Resistance of a material always decreases if  

    (a) Number of free electrons becomes less

    (b) Temperature of the material is decreased

    (c) Temperature of the material is increased

    (d) Number of free electrons becomes more

Ans: - (d).

 

Q. Variable resistance is

    (a) Wire wound resister

    (b) Thick film resistor

     (c) Thin film resistor

     (d) All above

Ans: - (a)

 Q. Which material has highest dielectric constant?

                   (a) Oil

                   (b) Glass

                   (c) Vacuum

                   (d) Water

Ans: - (c)

 Q Heat in the conductor is produced on the passage of electric current due to conductor possessing

                   (a) Capacitance

                   (b) Inductance

                   (c) Impedance

                   (d) Resistance

Ans: - (d)

Q. Two parallel conductors carrying current in the opposite direction will produce mutual

                   (a) Attraction

                   (b) Repulsion

                   (c) No effect

                   (d) Depends on situation

Ans: - (b)

 

Q. In case of liquids, ohm’s law is

                   (a) Fully obeyed

                   (b) No relation between current and potential difference

                   (c)  Partially obeyed

                             (d) Not obeyed at all

 Ans: - (a)

 

Q. Current flows between two points due to difference in

                   (a) Resistance

                   (b) Potential difference

                   (c) Charge

                   (d) None

Ans: (b)

 

Q. The ratio of mass of proton and that of electron is roughly

                   (a) 184        (b) 1800   (c) 1840   (d) 84

Ans: (c)

 

Q. Semiconductors have the value of temperature coefficient of resistance:

                   (a) Negative       (b) Positive

                   (c) Zero              (d) none

 Ans: - (b)

 Q. The current in the circuit is constant and resistance is doubled then power increases

                   (a) ½ times

                   (b) 2 times

                   (c) 4 times

                   (d) ¼ times

Ans: - (b)

 

Q. If temperature is increased then resistance of carbon

                   (a) Increases

                   (b) Becomes constant

                   (c) Decreases

                   (d) Remains same

Ans: - (c) Decreases

 

Q. Two 0.5 kilo ohms, 1W resistors are connected in series. They have equivalent resistance of   1.0 kilo ohms then power consumed will be

                   (a) .25 W     (b) 1.0 W

                   (c) 10 W      (d) 25 W

Ans: - (a)

 

Q. Specific resistance of a substance is expressed in

                   (a) m/ohms    (b) ohm/m

                   (c) k/ohm       (d) ohm/k

Ans: - (b)

 

Q. Which material is not used as the fuse material?

(a) Silicon         (b) Carbon

                   (c) Aluminum   (d) Copper

Ans: - (b)

 

Q. The electric field strength of a charge

                   (a) Decreases with distance

                   (b) Increases with distance

                   (c) Decreases with square of the distance

                   (d) Increases with square of distance  

Ans:-  (c)

Q. Electrical appliances are not connected in series because

                   (a) Don’t makes the appliances independent to each other

                   (b)  Power loss is more

                   (c) Provide high resistance

                   (d) None

Ans: - (a)

 

Q. The e.m.f. of a cell depends upon: -

                   (a) External resistance

                   (b) Internal resistance

                   (c) Current in the cell

                   (d) Electrode of the cell

Ans: (c)

 

Q. Kirchhoff’s current law at the junction deals with

                   (a) Conservation of energy

                   (b) Conservation of charge

                   (c) Conservation of momentum

                   (d) None

Ans: - (b)