01) Two 100W, 200V lamps are connected in series across a 200V supply. The total power consumed by each lamp will be in Watts :-
A) 25 Watts
B) 50 Watts
C) 100 Watts
D) 200 Watts
02) Two electric bulbs have transparent filament of same thickness. It one of them gives 60 W & other gives 100 W, then-
A) 60 W lamp filament has shorter length
B) 100 W lamp filament has longer length
C) 60 W lamp filament has longer length
D) 60 W & 100 W lamp filament have equal length
03) Bulb in street lighting are connected in
C) Series parallel
D) end of end
04) A piece of copper and another piece of germanium are cooled from room temperature to 80K. The resistance of
A) each of them increases.
B) each of them decreases.
C) copper increases and germanium decreases.
D) copper decreases and germanium increases.
05) If a large resistance is connected parallel a small resistance then net resistance will be
A) Greater than the large resistance
B) Smaller than the small resistance
C) Smaller than the greater but larger than the smaller resistance
D) None of the above option
06) The speed of a DC motor is
A) Directly proportional to flux and inversely proportional to back emf.
B) Directly proportional to both back emf and flux.
C) Directly proportional to back emf and flux.
D) Directly proportional to back emf and inversely proportional flux.
07) In which braking back emf exceeds supply voltage?
D) None of these.
08) Third pin of a 3 pin plug is thicker and longer due to
A) for designing purpose.
B) for protection purpose.
C) all pins are of same size.
D) none of these.
09) Power factor can be defined as
A) both option B and C.
B) cosine of angle between voltage and current.
C) ratio of resistance versus impedance.
D) sine of voltage and current.
10)A 60 Hz frequency voltage would case a bulb to turn on and off
A) 60 times per second.
B) 120 times per second.
C) 70 times per second.
D) 80 times per second.