Electronics and Communications TNPSC Group 1 Questions

Electronics and Communications MCQ Questions

7.
Electronic devices that convert D.C. power into A.C. power are called
A.
Converters
B.
Transformer
C.
Inverters
D.
Rectifiers
ANSWER :
C. Inverters
8.
Which of the following is an insulator?
A.
Aluminium
B.
Copper
C.
Glass
D.
Silver
ANSWER :
C. Glass
9.
A transformer
A.
transforms energy
B.
transforms frequency
C.
transform voltage
D.
generates induced e.m.f.
ANSWER :
D. generates induced e.m.f.
10.
Can D.C. voltage be used in a transformer
A.
yes
B.
no
C.
some times
D.
None of these
ANSWER :
B. no
11.
In a step-up transformer, the number of turns
A.
in the primary is more than the secondary
B.
in the secondary is more than in the primary
C.
is same both in the primary and the secondary
D.
None of these
ANSWER :
B. in the secondary is more than in the primary
12.
Two wires have their lengths,diameters and resistivities, all in the ratio of 1:2. If the resistance of the thinner wire is 10ohms,the resistance of the thicker wire shall be
A.
5 ohms
B.
10 ohms
C.
20 ohms
D.
40 ohms
ANSWER :
B. 10 ohms