Four charges q, 2q, 3q and 4q are located at the vertices of a square of side a (as shown in the given figure). k is the electrostatic constant. What is the sum of the magnitude of forces exerted on each charge?
An electron is held freely by the application of a uniform electric field directed vertically upwards.What is the magnitude of the electric field that is balancing the electron?
2.34 × 10−11 N C−1
3.62 × 10−11 N C−1
4.21 × 10−11 N C−1
5.58 × 10−11 N C−1
Two charges of amount +5 µC and −5 µC are located 0.05 cm apart from each other form an electric dipole. The dipole is held at an angle of 60° in a uniform electric field of 2.1 × 105 N C−1. What is the value of the torque acting on the dipole ?
2.1 × 10−4 N m
4.5 × 10−4 N m
7.2 × 10−4 N m
9.1 × 10 -4 N m
A charge experiences a force of 32 N as it is placed at a certain distance on the axial line of an electric dipole.What will be the force on the charge if its distance from the dipole is halved?
64 N
128 N
256 N
512 N
A coil of resistance R and inductance L is connected to a battery of e.m.f. E volts. The final current in the coil is
Two charged balls are suspended from a hinge by two threads of equal lengths. Mass of both the balls is 200 g. The amount of charges on both the balls is the same. At translational equilibrium, the balls are separated by a distance of 0.8 m, as shown in the given figure. What is the magnitude of charge on each ball?
4.33 µC
8.97 µC
17.16 µC
34.48 µC
An electron accelerated through 30-kV, in a cathode ray oscilloscope, enters a system of deflecting plates. The deflecting field between the plates is 24 kV m−1. The length of the deflecting plates is 0.06 m and the total deflection produced in the path of the electron on a screen is 9 mm.What is the distance of the screen from the near end of the plates?
0.35 m
0.38 m
0.40 m
0.45 m
The electric field intensity of a point P at a distance of 0.30 m from the centre of a Gaussian charged sphere of radius 0.20 m is 2.5 × 103 N C-1, directed radically outwards. What is the electric flux emanating through the given Gaussian surface?
2.82 × 103 N m2C-1
1.25 × 103 N m2C-1
0.63 × 103 N m2 C-1
0.31 × 103 N m2C-1
Two point charges +1.5 µC and −0.5 µC are located 1 m apart. There is a point P on the line joining the charges where the net potential is zero. What is the distance of point P from charge +1.5 µC ?
0.50 m
0.75 m
0.25 m
What is the force between an electron and an alpha particle separated by a distance 2 Å?
5.76 × 10−9 N of attractive nature
5.76 × 10−9 N of repulsive nature
11.52 × 10−9 N of attractive nature
11.52 × 10−9 N of repulsive nature
