Physics-
General
Easy
Question
In figure, a lamp P is in series with an iron-core inductor L. When the switch S is closed, the brightness of the lamp rises relatively slowly to its full brightness than it would do without the inductor. This is due to
- the low resistance of P
- the induced-emf in L
- the low resistance of L
- the high voltage of the battery B
The correct answer is: the induced-emf in L
Related Questions to study
physics-
In figure, the switch S is closed so that a current flows in the iron-core inductor which has inductance L and the resistance R. When the switch is opened, a spark is obtained in it at the contacts. The spark is due to
In figure, the switch S is closed so that a current flows in the iron-core inductor which has inductance L and the resistance R. When the switch is opened, a spark is obtained in it at the contacts. The spark is due to
physics-General
physics-
An inductor L, a resistance R and two identical bulbs B1 and B2 are connected to a battery through a switch S as shown in the figure. The resistance of coil having inductance L is also R. Which of the following statement gives the correct description of the happenings when the switch S is closed?
An inductor L, a resistance R and two identical bulbs B1 and B2 are connected to a battery through a switch S as shown in the figure. The resistance of coil having inductance L is also R. Which of the following statement gives the correct description of the happenings when the switch S is closed?
physics-General
physics-
At a moment (t = 0) when charge on capacitor C1 is zero, the switch is closed. If I0 be the current through inductor at that instant, for t > 0,
At a moment (t = 0) when charge on capacitor C1 is zero, the switch is closed. If I0 be the current through inductor at that instant, for t > 0,
physics-General
physics-
A circuit element is placed in a closed box. At time t=0, constant current generator supplying a current of 1 amp, is connected across the box. Potential difference across the box varies according to graph shown in figure. The element in the box is :
A circuit element is placed in a closed box. At time t=0, constant current generator supplying a current of 1 amp, is connected across the box. Potential difference across the box varies according to graph shown in figure. The element in the box is :
physics-General
physics-
A conducting ring of radius a is rotated about a point O on its periphery as shown in the figure in a plane perpendicular to uniform magnetic field B which exists everywhere. The rotational velocity is 
.
Choose the correct statement(s) related to the magnitude of potential differences
A conducting ring of radius a is rotated about a point O on its periphery as shown in the figure in a plane perpendicular to uniform magnetic field B which exists everywhere. The rotational velocity is .
Choose the correct statement(s) related to the magnitude of potential differences
physics-General
physics-
A conducting rod PQ of length L = 1.0 m is moving with a uniform speed v = 20 m/s in a uniform magnetic field B = 4.0 T directed into the paper. A capacitor of capacity C = 10 
is connected as shown in figure. Then
A conducting rod PQ of length L = 1.0 m is moving with a uniform speed v = 20 m/s in a uniform magnetic field B = 4.0 T directed into the paper. A capacitor of capacity C = 10 is connected as shown in figure. Then
physics-General
physics-
In the previous question, if B is normal to the plane of the rails
In the previous question, if B is normal to the plane of the rails
physics-General
physics-
AB and CD are smooth parallel rails, separated by a distance l, and inclined to the horizontal at an angle 
. A uniform magnetic field of magnitude B, directed vertically upwards, exists in the region. EF is a conductor of mass m, carrying a current i. For EF to be in equilibrium,
AB and CD are smooth parallel rails, separated by a distance l, and inclined to the horizontal at an angle . A uniform magnetic field of magnitude B, directed vertically upwards, exists in the region. EF is a conductor of mass m, carrying a current i. For EF to be in equilibrium,
physics-General
physics-
Two circular coils A and B are facing each other as shown in figure. The current i through A can be altered
Two circular coils A and B are facing each other as shown in figure. The current i through A can be altered
physics-General
physics-
A conducting wire frame is placed in a magnetic field which is directed into the paper. The magnetic field is increasing at a constant rate. The directions of induced currents in wires AB and CD are
A conducting wire frame is placed in a magnetic field which is directed into the paper. The magnetic field is increasing at a constant rate. The directions of induced currents in wires AB and CD are
physics-General
physics-
The adjoining figure shows two different arrangements in which two square wire frames are placed in a uniform constantly decreasing magnetic field B.
If I1 and I2 are the magnitudes of induced current in the cases I and II, respectively, then
The adjoining figure shows two different arrangements in which two square wire frames are placed in a uniform constantly decreasing magnetic field B.
If I1 and I2 are the magnitudes of induced current in the cases I and II, respectively, then
physics-General
physics-
The adjoining figure shows two different arrangements in which two square wire frames are placed in a uniform constantly decreasing magnetic field B.
The direction of induced current in the case II is
The adjoining figure shows two different arrangements in which two square wire frames are placed in a uniform constantly decreasing magnetic field B.
The direction of induced current in the case II is
physics-General
physics-
The adjoining figure shows two different arrangements in which two square wire frames are placed in a uniform constantly decreasing magnetic field B.
The direction of induced current in the case I is
The adjoining figure shows two different arrangements in which two square wire frames are placed in a uniform constantly decreasing magnetic field B.
The direction of induced current in the case I is
physics-General
physics-
The adjoining figure shows two different arrangements in which two square wire frames are placed in a uniform constantly decreasing magnetic field B.
The value of magnetic flux in each case is given by
The adjoining figure shows two different arrangements in which two square wire frames are placed in a uniform constantly decreasing magnetic field B.
The value of magnetic flux in each case is given by
physics-General
physics-
The circuit shown is in a uniform magnetic field that is into the page and is decreasing in magnitude at the rate of 150 tesla/second. The ideal ammeter reads
The circuit shown is in a uniform magnetic field that is into the page and is decreasing in magnitude at the rate of 150 tesla/second. The ideal ammeter reads
physics-General
