Which of the following material has nearly zero temperature co-efficient of resistance?
Copper
Manganin
Porcelain
Carbon
Manganin
You have to replace 1500 Q resistor in radio. You have no 1500 Q resistor but have several 1000 Q ones which you would connect
two in parallel and one in series
two in parallel
three in parallel
three in series
two in parallel and one in series
A closed switch has a resistance of
infinity
about 500 ohms
about 50 ohms
zero
zero
The hot resistance of the bulb’s filament is higher than its cold resistance because the temperature co-efficient of the filament is
zero
negative
positive
about 2 ohms per degree
positive
When one leg of parallel circuit is opened out the total current will
decrease
become zero
increase
reduce
decrease
In a lamp load when more than one lamp are switched on the total resistance of the load
decreases
remains same
increases
none of the above
decreases
Two lamps 100 W and 40 W are connected in series across 230 V (alternating). Which of the following statement is correct ?
40 W lamp will fuse
40 W lamp will glow brighter
100 W lamp will glow brighter
Both lamps will glow equally bright
40 W lamp will glow brighter
Resistance of 220 V 100 W lamp will be
484 ft
4.84 Q
48.4 Q
4840 Q
484 ft
In the case of direct current
magnitude of current remains constant
magnitude of current changes with time
magnitude and direction of current changes with time
magnitude and direction of current remains constant
magnitude and direction of current remains constant
When electric current passes through a bucket full of water lot of bubbling is observed. This suggests that the type of supply is
A.C.
any of above two
D.C.
none of the above
D.C.
पोस्ट अच्छी लगी हो तो प्लीज नीचे दिए गए लिंक पर क्लिक कर शेयर जरुर करें
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