Advertisements
Advertisements
Question
A coil Q is connected to low voltage bulb B and placed near another coil P as shown in the figure. Give reasons to explain the following observations:
(a) The bulb ‘B’ lights
(b) Bulb gets dimmer if the coil Q is moved towards left.
Advertisements
Solution
(a) The A.C. source creates a varying magnetic field in coil P. This varying magnetic field of P is linked to coil Q. Hence, an induced current is produced in Q, which lights bulb B.
(b) As coil Q moves away from P, the rate of variation of magnetic flux changes. Therefore, the induced e.m.f. inside coil Q decreases and bulb B gets dimmer.
APPEARS IN
RELATED QUESTIONS
Output characteristics of an n-p-n transistor in CE configuration is shown in the figure.
Determine:
(i) dynamic output resistance
(ii) dc current gain and
(iii) ac current gain at an operating point VCE = 10 V, when IB = 30 μA.
How does the sign of the phase angle `phi`, by which the supply voltage leads the current in an LCR series circuit, change as the supply frequency is gradually increased from very low to very high values.
The vertical component of a voltage phasor V at any instant represents ______.
What does the vertical component of a phasor give at any instant?
At what angular velocity does a phasor rotate about the origin?
What is the length of a voltage phasor?
What is the length of a current phasor?
Which expression gives the vertical component of a current phasor?
In an AC circuit with a pure resistor, what is the relationship between current and the applied AC voltage?
Does the in-phase relationship of a pure resistor hold for any combination of a pure resistor, a pure inductor, and a pure capacitor?
