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This section includes 1177 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics knowledge and support exam preparation. Choose a topic below to get started.
101. |
Rheostat is added to increase field excitation. |
A. | in the circuit of the alternator |
B. | in the supply circuit |
C. | in the field of shunt generator |
D. | in the circuit of the armature |
Answer» B. in the supply circuit | |
102. |
What is the material of transformer core? |
A. | silicon-steel |
B. | silicon |
C. | cobalt |
D. | aluminum |
Answer» B. silicon | |
103. |
Transformers that convert low voltage to high voltage are called? |
A. | step up |
B. | Step down |
C. | both A and B |
D. | none of these |
Answer» B. Step down | |
104. |
Substances split into their ions is called? |
A. | Replacement |
B. | polarization |
C. | Ionization |
D. | electrolysis |
Answer» E. | |
105. |
Using Damper Winding in Alternator? |
A. | the machine becomes more balanced |
B. | The whirlpool current decreases |
C. | Hating ends |
D. | armature reaction decreases |
Answer» D. armature reaction decreases | |
106. |
Which lamp method should be adopted if the synchronizing three phase alternator is to be done? |
A. | One Dark Two Bright Lamp Method |
B. | Bright Lamp Method |
C. | dark lamp method |
D. | suitable all |
Answer» E. | |
107. |
Driven e in rotating machines |
A. | Working flux lags from to 90॰ |
B. | Working flux to 90 leads |
C. | Working flux occurs in the art of |
D. | Working flux lags from to 180॰ |
Answer» B. Working flux to 90 leads | |
108. |
Which of the following cannot be a permanent indicator of a substance? |
A. | stainless steel |
B. | soft iron |
C. | hardened steel |
D. | Nickel to Volt Alloy |
Answer» C. hardened steel | |
109. |
What is the unit of ampere-hour? |
A. | Power |
B. | amount of electricity |
C. | strength of current |
D. | energy |
Answer» C. strength of current | |
110. |
Is there a potential difference? |
A. | resistance between two points |
B. | difference of electric potential between two points in an electric circuit |
C. | current difference between two points |
D. | none in suitable |
Answer» D. none in suitable | |
111. |
e of a magnetic circuit |
A. | electromotive force |
B. | of the stream |
C. | of force |
D. | of volts |
Answer» B. of the stream | |
112. |
Are wires used for staywire and earthing? |
A. | of brass wire |
B. | of copper |
C. | of GI wire |
D. | of aluminum wire |
Answer» C. of GI wire | |
113. |
Kitkat fuse over headline insulators are made from? |
A. | asbestos |
B. | micanite |
C. | glass |
D. | parsley |
Answer» E. | |
114. |
How to check the charging status of the battery? |
A. | by micrometer |
B. | from phase tester |
C. | With High Rate Cell Discharge Tester |
D. | by hygrometer |
Answer» D. by hygrometer | |
115. |
After a lead acid battery is fully charged, the active substances on the positive and negative plates are? |
A. | Lead Sulphate and Lead Peroxide |
B. | lead sulfate and lead |
C. | pure lead and lead oxide |
D. | lead peroxide and pure lead |
Answer» E. | |
116. |
If both ends of a charged capacitor are shorted? |
A. | voltage will be generated |
B. | There will be sparking |
C. | Nothing will happen |
D. | torque will be |
Answer» C. Nothing will happen | |
117. |
Studs are made in a three point starter? |
A. | of tungsten |
B. | of copper |
C. | of hard brass |
D. | of aluminum |
Answer» D. of aluminum | |
118. |
What is the amount of heat required to raise the temperature of one gram of water by 1॰C? |
A. | one calorie |
B. | one joule |
C. | 5 calories |
D. | suitable all |
Answer» B. one joule | |
119. |
Blue glow in Mercury Arc rectifier? |
A. | due to ionization |
B. | electron current is caused by |
C. | caused by high temperature |
D. | suitable all |
Answer» B. electron current is caused by | |
120. |
In table fan there is uneven air gap between stator and rotor, what is the disadvantage in this? |
A. | motor burn out |
B. | magnetizing hanning |
C. | low speed |
D. | speed up and down |
Answer» C. low speed | |
121. |
Coiled filament is used? |
A. | in low power lamp |
B. | in gas filled lamp |
C. | in high power lamps |
D. | in white light bulbs |
Answer» C. in high power lamps | |
122. |
A device that can increase or decrease voltage and current (without changing power) without changing the frequency is called? |
A. | DC. Motor |
B. | generator |
C. | AC Motor |
D. | Transformer |
Answer» E. | |
123. |
Lamps are used in light houses, search lights, cinema projectors? |
A. | tungsten filament |
B. | HPMV Lamp |
C. | arc lamp |
D. | neon lamp |
Answer» D. neon lamp | |
124. |
What are NPN and PNP? |
A. | Transistor |
B. | valve |
C. | Resistance |
D. | Capacitors |
Answer» B. valve | |
125. |
The rotor winding of a synchronous motor is excited by |
A. | dc supply from exciter |
B. | ac supply |
C. | induction of stator current |
D. | cruising area |
Answer» B. ac supply | |
126. |
Three delta connected identical coils draw 400V, 5KW power and 90A line current from 3 supplies. What is the total KVA taken by the coils? |
A. | 1.0KVA |
B. | 2.5 KVA |
C. | 30KVA |
D. | 60KVA |
Answer» C. 30KVA | |
127. |
The resistance of the silver wire increases? |
A. | when the radius is doubled |
B. | on increasing length |
C. | on decreasing length |
D. | when the diameter is greater |
Answer» C. on decreasing length | |
128. |
Should the fuse always be connected? |
A. | in parallel with the neutral conductor |
B. | in the rank of apathetic driver |
C. | in parallel to the live wire |
D. | in series with live wire |
Answer» E. | |
129. |
This type of circuit breaker does not have any repairable parts. |
A. | air circuit breaker |
B. | oil circuit breaker |
C. | air blast circuit breaker |
D. | miniature circuit breaker |
Answer» E. | |
130. |
high voltage d |
A. | open tapered |
B. | semi-closed type |
C. | closed type |
D. | open doublet |
Answer» E. | |
131. |
The function of a protection relay is performed in a transformer. |
A. | Exploin Vent |
B. | temperature gauge |
C. | Bacchus relay |
D. | Earth point |
Answer» D. Earth point | |
132. |
A 230 V, dc series motor is connected to 230 V, ac, the motor? |
A. | run with low efficiency |
B. | won't work |
C. | speed will decrease |
D. | none of the suitable |
Answer» B. won't work | |
133. |
International ohm is defined as the resistance of? |
A. | unit length of metallic wire |
B. | Columns of mercury |
C. | copper cubes |
D. | cubes of carbon |
Answer» C. copper cubes | |
134. |
A plywood board is to be heated to 100॰. What would be the appropriate heating method for this? |
A. | resistive heating |
B. | arc heating |
C. | induction heating |
D. | none of the suitable |
Answer» D. none of the suitable | |
135. |
more capacity d |
A. | swinburne test |
B. | blocked rotor test |
C. | hopkinson test |
D. | ward leonard test |
Answer» B. blocked rotor test | |
136. |
At what distance is the wiring from the ceiling to the wall? |
A. | 1 meter |
B. | 1/2 meter |
C. | 45 cm. |
D. | m 2 |
Answer» D. m 2 | |
137. |
Frequency is controlled? |
A. | By turning off the alternator |
B. | at the speed of the primer |
C. | by Exciter |
D. | suitable all |
Answer» E. | |
138. |
Which of the following is the correct temperature to operate a tungsten filament lamp filled with gas? |
A. | 1200॰C |
B. | 1035॰C |
C. | 2300॰C |
D. | 1500॰C |
Answer» D. 1500॰C | |
139. |
Used in modern equipment? |
A. | तंगर दिष्टकारी |
B. | mercury arc rectifier |
C. | metallic rectifier |
D. | solid state rectifier |
Answer» E. | |
140. |
For what tasks is the heating method by radiation suitable |
A. | melting ferrous metals |
B. | Boiling of liquids in an electric kettle |
C. | annealing of metals |
D. | paint and varnish drying |
Answer» E. | |
141. |
A hole is made in the vent plug, in the cover of the battery? |
A. | To protect the battery and drain the gas |
B. | For beauty |
C. | to let out gas |
D. | suitable all |
Answer» B. For beauty | |
142. |
Where are fuel cells used? |
A. | in turbine operation |
B. | in nuclear reactor |
C. | Gemini space craft |
D. | none of the suitable |
Answer» D. none of the suitable | |
143. |
What is the diameter of a fluorescent tube? |
A. | 30MM to 70MM |
B. | 20MM to 40MM |
C. | 60MM to 100MM |
D. | 40MM to 60MM |
Answer» C. 60MM to 100MM | |
144. |
In the rotor of squirrel phase motor, the rod is placed between the laminated core? |
A. | Eureka's |
B. | nichrome key |
C. | of tungsten |
D. | of copper |
Answer» E. | |
145. |
What is required for automatic control of furnace temperature? |
A. | Heating Element of Variable Resistance |
B. | Thermostat |
C. | auto transformer |
D. | thermocouple |
Answer» C. auto transformer | |
146. |
What is the maximum voltage of LED? |
A. | 5V |
B. | 8V |
C. | 10V |
D. | 12V |
Answer» C. 10V | |
147. |
The impedance of the operation amplifier? |
A. | is high |
B. | is below |
C. | Zero |
D. | very low but not zero |
Answer» E. | |
148. |
What is the appropriate method to heat insulators and plastic materials? |
A. | by oil ignition method |
B. | resistance method |
C. | dielectric thermal method |
D. | by coal furnace |
Answer» D. by coal furnace | |
149. |
Which of the following substances will have the lowest temperature range? |
A. | eureka |
B. | nichrome |
C. | Canthal |
D. | Carbon |
Answer» B. nichrome | |
150. |
What if a single-phase, 230 volt, 48 inch ceiling fan is operated at 120 volts? |
A. | it will run at normal speed but get very hot |
B. | it will slow down |
C. | it won't work |
D. | it will run at normal speed |
Answer» C. it won't work | |