The inductance of an iron-core coil decreases if
Answer: Option A
Explanation:
Flux is directly proportional to no.of turns.
An 18 V power supply is connected across a coil with a winding resistance of 180 Ω. Current flow in the coil is
Answer: Option C
I = V/R. = 18/180. = 0.1A or 100mA.
Three 15 mH inductors are in series. The total inductance is
The total inductance=L1+L2+L3 =15+15+15 The total inductance = 45 mH
When the current through an inductor decreases, the amount of energy stored in the electromagnetic field
Answer: Option B
As energy stored in a inductor=1/2*L*I^2 so if current decreases energy stored also decreases.
The current through a 120 mH coil is changing at a rate of 150 mA/s. The voltage induced across the coil is
The inductance is 120 mH = 120*10^-3H. The current is 150 mA/sec =150*10^-3A/sec. V = L(di/dt). = (120*10^-3)*(150*10^-3). = 0.0018v.+ = 18mV
