Company: Bharat Sanchar Nigam Ltd
Maxwell?s loop current method of solving electrical networks ?
a) uses branch currents
b) utilizes kirchhoff?s voltage law
c) is confined to single-loop circuits
d) is a network reduction method
Answer: b)
A transmission line of characteristic impedance Z0 = 50 ohms, phase velocity Vp = 2 x 108 m/s and length l = 1m is terminated by a load ZL= ( 30 ? j 40 ) ohms. The input impedance of the line for a frequency of 100 MHz will be
a)(30 + j40 ) ohms
b)( 30 ? j40 ) ohms
c)(50 + j40 ) ohms
d)(50 ? j40 ) ohms
Answer: b)
For an elliptically polarized wave incident on the interface of a dielectric at the Brewster angle then the reflected wave will be-
a) Elliptically polarized
b) Linearly polarized
c) Right circularly polarized
d) Left circularly polarized
Answer: b)
A yagi antenna has a driven antenna-
a) Only
b) With a reflector
c) With one or more directors
d) With a reflector and one or more directors
Answer: d)
The number of lobes on each side of a 3l resonant antenna is ?
a) 3
b) 6
c) 2
d) 1
Answer: b)
The electric field intensity of a Hertizian dipole at a remote point varies as –
Radiation resistance of a half wave folded dipole is –
a) 72 W
b) 144W
c) 288 W
d) 216W
Answer: 1/r
When a carrier wave is modulated at 100% it?s power is increased by –
a)100%
b)150 %
c)50%
d)0%
Answer: c)
On a clear sky day, the atmospheric radio noise is strongest –
a) During morning hours
b) Around mid-day
c) During nights
d) In the afternoon
Answer: c)
TV broadcasting system in India is as per CCIR –
a) System B
b) System I
c) System M
d) System X
Answer: b)
For the safety measurement of the internal resistance of a 25-0-25 mA meter, a laboratory multimeter whose sensitivity is equal to ?
a) 1k ohm/volt can be used
b) 10 k ohm/volt can be used
c) 100 k ohm/volt can be used
d) 200 k ohm/volt can be used
Answer: d)
In order to measure moisture in wood the most suitable method is ?
a) Electrical conduction
b) Electrical ? capacitive
c) Absorption of radiation
d) Equilirium- moisture vs humidity
Answer: a)
The flow rate of electrically conducting liquid without any suspended particle cannot be measured by ?
a) turbine flow meters
b) electromagnetic flow meters
c) ultrasonic flow meters
d) thermistor based heat loss flow meters
Answer: d)
The most useful transducer for displacement sensing with excellent sensitivity, linearity and resolution is ?
a) an incremental encoder
b) an abosolute encoder
c) LVDT
d) a strain gauge
Answer: c)
When variable reluctance type tachometer has 150 teeth on the rotor & the counter records 13,500 pulses per second then the rotational speed will be?
a) 4800 rpm
b) 5400 rpm
c) 6000 rpm
d) 7200 rpm.
Answer: b)
41. On a voltage scale, zero dB m in a 600-ohm system could refer to ?
a) 1.732 V
b) 1.0 V
c) 0.7746 V
d) 0.5V
Answer: b)
One of the following devices which is required in addition in order to measure pressure using LVDT is-
a) strain gauge
b) pitot tube
c) Bourden tube
d) Rotameter
Answer: c)
It is required to measure temperature in the range of 13000 C to 15000 c) The most suitable thermocouple to be used as a transducer would be ?
a) chromel – constantan
b) Iron – constantan
c) chromel – alumel
d) platinum- rhodium
Answer: d)
In a CSI if frequency of output voltage is f Hz, then frequency of input voltage to CSI is-
a) f
b) 2 f
c) f/2
d) 3 f
Answer: b)
Identify the type of chipper in the given circuit
a) Type A chopper
b) Type B chopper
c) Type C chopper
d) Type D chopper
Answer: b)
Maximum value of charging resistance in an UJT is associated with-
a) peak point
b) valley point
c) any point between peak and valley
d) after the valley point
Answer: a)