With three resistances connected in parallel if each dissipates 20 W the total power supplied by the voltage source equals
60 W
20 W
10 W
40 W
60 W
A thermistor has
variable temperature coefficient
zero temperature coefficient
positive temperature coefficient
negative temperature coefficient
zero temperature coefficient
If/ R and t are the current resistance and time respectively then according to Joule’s law heat produced will be proportional to
I2Rt
I2Rf
I2R2t
I2R2t*
I2Rt
A substance whose molecules consist of dissimilar atoms is called
insulator
super-conductor
semi-conductor
compound
compound
International ohm is defined in terms of the resistance of
a cube of carbon
a cube of copper
a column of mercury
the unit length of wire
a column of mercury
Three identical resistors are first connected in parallel and then in series. The resultant resistance of the first combination to the second will be
1/9 times
3 times
1/3 times
9 times
1/9 times
Nichrome wire is an alloy of
nickel and chromium
chromium and vanadium
lead and zinc
copper and silver
nickel and chromium
Switching of a lamp in house produces noise in the radio. This is because switching operation produces
none of the above
arcs across separating contacts
mechanical noise of high intensity
both mechanical noise and arc between contacts
arcs across separating contacts
Sparking occurs when a load is switched off because the circuit has high
inductance
resistance
capacitance
impedance
inductance
A field of force can exist only between
two metal particles
two atoms
two molecules
two ions
two ions
पोस्ट अच्छी लगी हो तो प्लीज नीचे दिए गए लिंक पर क्लिक कर शेयर जरुर करें
0 Comments