A charge Q is uniformly distributed over a long rod AB of length L, as shown in the figure. The electric potential at the poing O lying at a distance L from the end A is :
As we discussed in
Potential Difference 

Charge on the element
Potential at 0
Option 1)
Option 2)
Option 3)
Option 4)
A parallel plate capacitor is made of two circular plates separated by a distance of 5 mm and with a dielectric of dielectric constant 2.2 between them. When the electric field in the dielectric is 310^{4} V/m, the charge density of the positive plate will be close to :
As we discussed in the concept
Infinite Plane Parallel sheets of charge 
If
and E_{Q} = 0

Charge density
=
Option 1)
Option 2)
Option 3)
Option 4)
Assume that an electric field exists in space. Then the potential difference V_{A}  V_{O}, where V_{O} is the potential at the origin and V_{A} the potential at x=2 m is :
120 J
120 J
 80 J
80 J
As we discussed in the concept
In space 
, ,

Option 1)
120 J
Option 2)
120 J
Option 3)
 80 J
Option 4)
80 J
The space between the plates of a parallel plate capacitor is filled with a ‘dielectric’ whose ‘dielectric constant’ varies with distance as per the relation :
The capacitance C, of this capacitor, would be related to its ‘vacuum’ capacitance C_{o} as per the relation :
As we discussed in
The boundary Conditions 

Capacitance of Conductor 
 wherein
C  Capacity or capacitance of conductor
V  Potential.
Given
S= surface area of plate.
here,
Option 1)
Option 2)
Option 3)
Option 4)
An object is dropped from a height h from the ground. Every time it hits the ground it looses 50% of its kinetic energy. The total distance covered as is :
3h
First is right answer, because every time it hit ground it cannot much distance
Assume that a neutron breaks into a proton and an electron. The energy released during this process is (Mass of neutron = 1.6725 x 10^{–27}kg; mass of proton = 1.6725 x 10^{–27}kg; mass of electron = 9 x 10^{–31} kg)
0.73 MeV
7.10 MeV
6.30 MeV
0.51 MeV
A player caught a cricket ball of mass 150 g moving at a rate of 20 m/s . If the catching process is completed in 0.1 s the force of the blow exerted by the ball on the hand of the player is equal to
300 N
150 N
3 N
30 N
An electric dipole has a fixed dipole moment , which makes angle θ with respect to xaxis. When subjected to an electric field it experiences a torque When subjected to another electric field it experiences a torque The angle θ is :
30^{0}
45^{0}
60^{0}
90^{0}
A fighter plane of length 20 m, wing span (distance from tip of one wing to the tip of the other wing) of 15 m and height 5 m is flying towards east over Delhi. Its speed is 240 ms^{−1}. The earth’s magnetic field over Delhi is 5×10^{−5} T with the declination angle ~ and dip of θ such that If the voltage developed is V_{B} between the lower and upper side of the plane and V_{W} between the tips of the wings then V_{B} and V_{W} are close to :
V_{B} = 45 mV ; V_{W} = 120 mV with right side of pilot at higher voltage
V_{B} = 45 mV ; V_{W} = 120 mV with left side of pilot at higher voltage
V_{B} = 40 mV ; V_{W} = 135 mV with right side of pilot at higher voltage
V_{B} = 40 mV ; V_{W} = 135 mV with left side of pilot at higher voltage
Figure shows a circular area of radius R where a uniform magnetic field is going into the plane of paper and increasing in magnitude at a constant rate. In that case, which of the following graphs, drawn schematically, correctly shows the variation of the induced electric field E(r) ?
A 2V battery is connected across AB as shown in the figure. The value of the current supplied by the battery when in one case battery’s positive terminal is connected to A and in other case when positive terminal of battery is connected to B will respectively be :
0.2 A and 0.1 A
0.4 A and 0.2 A
0.1 A and 0.2 A
0.2 A and 0.4 A
Three straight parallel current carrying conductors are shown in the figure. The force experienced by the middle conductor of length 25 cm is :
3 x 10^{4} N toward right
6 x 10^{4} N toward left
9 x 10^{4} N toward left
Zero
The circuit shown here has two batteries of 8.0 V and 16.0 V and three resistors 3 , 9 and 9 and a capacitor 5.0 F.
How much is the current I in the circuit in steady state ?
1.6 A
0.67 A
2.5 A
0.25 A
As we have learned
In closed loop 
 wherein
since in steady state current through capacitor is 0
USing kirchoff's rule
169I 3I 8V = 0 or I = 8/12 A = 2/3 A
= 0.67 A
Option 1)
1.6 A
Option 2)
0.67 A
Option 3)
2.5 A
Option 4)
0.25 A
Two identical wires A and B, each of length ‘’, carry the same current I. Wire A is bent into a circle of radius R and wire B is bent to form a square of side ‘a’. If B_{A} and B_{B} are the values of magnetic field at the centres of the circle and square
respectively, then the ratio is
The box of a pin hole camera, of length L, has a hole of radius a. It is assumed that when the hole is illuminated by a parallel beam of light of wavelength λ the spread of the spot (obtained on the opposite wall of the camera) is the sum of its geometrical spread and the spread due to diffraction. The spot would then have its minimum size (say b_{min}) when :
In the following, which one of the diodes is reverse biased?
A particle is released on a vertical smooth semicircular track from point X so that OX makes angle from the vertical (see figure). The normal reaction of the track on the particle vanishes at point Y where OY makes angle with the horizontal. Then :
The graph between angle of deviation and angle of incidence for a triangular prism is represented by :
If a white light is used in Young’s double slit experiment, then a very large number of coloured fringes can be seen:
With first order violet fringes being closer to the central white fringes
First order red fringes being closer to the central white fringes
With a central white fringe
With a central black fringe
A converging lens is used to form an image on a screen. When the upper half of the lens is covered by an opaque screen:
half of the image will disappear
image will not form on the screen
intensity of image will increase
intensity of image will decrease