Physics-
General
Easy
Question
As shown in the figure, P and Q are two coaxial conducting loops separated by some distance. When the switch S is closed, a clockwise current 
flows in P (as seen by E) and an induced current 
flows in Q. The switch remains closed for a long time. When S is opened, a current 
flows in Q. Then the directions of and (as seen by E) are
- Respectively clockwise and anticlockwise
- Both clockwise
- Both anticlockwise
- Respectively anticlockwise and clockwise
The correct answer is: Respectively anticlockwise and clockwise
When switch S is closed magnetic field lines passing through Q increases in the direction from right to left. So, according to Lenz’s law induced current in Q i.e. will flow in such a direction so that the magnetic field lines due to passes from left to right through Q. This is possible when flows in anticlockwise direction as seen by E. Opposite is the case when switch S is opened i.e. will be clockwise as seen by E
Related Questions to study
Maths-
A particle moves along a line by 
then S is decreasing when t 
A particle moves along a line by then S is decreasing when t
Maths-General
maths-
Assertion: f(x) = ln 
is an odd function.
Reason: Let f be a function with domain D such that
i) x D 
– x D
ii) f(–x) = – f(x) and
iii) f (0) = 0 or f (0) is not defined
Then the function f(x) is an odd function
Assertion: f(x) = ln is an odd function.
Reason: Let f be a function with domain D such that
i) x D – x D
ii) f(–x) = – f(x) and
iii) f (0) = 0 or f (0) is not defined
Then the function f(x) is an odd function
maths-General
physics-
A conducting rod of length 2l is rotating with constant angular speed w about its perpendicular bisector. A uniform magnetic field 
exists parallel to the axis of rotation. The e.m.f. induced between two ends of the rod is
A conducting rod of length 2l is rotating with constant angular speed w about its perpendicular bisector. A uniform magnetic field exists parallel to the axis of rotation. The e.m.f. induced between two ends of the rod is
physics-General
physics-
A metallic square loop ABCD is moving in its own plane with velocity v in a uniform magnetic field perpendicular to its plane as shown in the figure. An electric field is induced
A metallic square loop ABCD is moving in its own plane with velocity v in a uniform magnetic field perpendicular to its plane as shown in the figure. An electric field is induced
physics-General
physics-
Two circular coils can be arranged in any of the three situations shown in the figure. Their mutual inductance will be
Two circular coils can be arranged in any of the three situations shown in the figure. Their mutual inductance will be
physics-General
physics-
A uniform but time-varying magnetic field B(t) exists in a circular region of radius a and is directed into the plane of the paper, as shown. The magnitude of the induced electric field at point P at a distance r from the centre of the circular region
A uniform but time-varying magnetic field B(t) exists in a circular region of radius a and is directed into the plane of the paper, as shown. The magnitude of the induced electric field at point P at a distance r from the centre of the circular region
physics-General
maths-
With the usual meaning for a, b, c and s if 
be the area of a triangle then the error in resulting from a small error in the measurement of c, is
With the usual meaning for a, b, c and s if be the area of a triangle then the error in resulting from a small error in the measurement of c, is
maths-General
physics-
Consider the situation shown in the figure. The wire AB is sliding on the fixed rails with a constant velocity. If the wire AB is replaced by semicircular wire, the magnitude of the induced current will
Consider the situation shown in the figure. The wire AB is sliding on the fixed rails with a constant velocity. If the wire AB is replaced by semicircular wire, the magnitude of the induced current will
physics-General
physics-
A thin semicircular conducting ring of radius R is falling with its plane vertical in a horizontal magnetic induction B. At the position MNQ, the speed of the ring is V and the potential difference developed across the ring is
A thin semicircular conducting ring of radius R is falling with its plane vertical in a horizontal magnetic induction B. At the position MNQ, the speed of the ring is V and the potential difference developed across the ring is
physics-General
physics-
An electron moves along the line AB, which lies in the same plane as a circular loop of conducting wires as shown in the diagram. What will be the direction of current induced if any, in the loop
An electron moves along the line AB, which lies in the same plane as a circular loop of conducting wires as shown in the diagram. What will be the direction of current induced if any, in the loop
physics-General
physics-
In the circuit shown switch k2 is open and switch k1 is closed at t = 0. At time t = to switch k1 is opened and switch k2 is simultaneously closed. The variation of inductor current with time is
In the circuit shown switch k2 is open and switch k1 is closed at t = 0. At time t = to switch k1 is opened and switch k2 is simultaneously closed. The variation of inductor current with time is
physics-General
physics-
An equilateral triangular loop having a resistance R and length of each side l is placed in a magnetic field which is varying at 
The induced current in the loop will be
An equilateral triangular loop having a resistance R and length of each side l is placed in a magnetic field which is varying at The induced current in the loop will be
physics-General
maths-
The area of the triangle formed by tangents drawn from the point (x1, y1) to the parabola y2 = 8x and its chord of contact is
The area of the triangle formed by tangents drawn from the point (x1, y1) to the parabola y2 = 8x and its chord of contact is
maths-General
physics-
A uniform but time varying magnetic field is present in a circular region of radius R. The magnetic field is perpendicular and into the plane of the loop and the magnitude of the field is increasing at a constant rate 
.There is a straight conducting rod of length 2R placed as shown in figure .The magnitude of induced emf across the rod is
A uniform but time varying magnetic field is present in a circular region of radius R. The magnetic field is perpendicular and into the plane of the loop and the magnitude of the field is increasing at a constant rate .There is a straight conducting rod of length 2R placed as shown in figure .The magnitude of induced emf across the rod is
physics-General
physics-
In the arrangement shown in the figure, uniform magnetic field B is upward to the plane of paper. Connecter AB is smooth and conducting, having mass m and length l. Initially spring has extension X0. Spring is non-conducting (neglect induction in spring). Connector is released at t = 0. Maximum charge on the capacitor is
In the arrangement shown in the figure, uniform magnetic field B is upward to the plane of paper. Connecter AB is smooth and conducting, having mass m and length l. Initially spring has extension X0. Spring is non-conducting (neglect induction in spring). Connector is released at t = 0. Maximum charge on the capacitor is
physics-General
