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
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 thin metal plates are placed close to each other. On the inner side, both plates have a surface charge density of 2.9 × 10−11 C m−2, but of opposite nature. Between the plates, what is the electric force exerted in per unit area ?
5.5 × 10 -11 N/m2
9.5 × 10 -11 N/m2
5.5 × 10 -12 N/m2
9.5 × 10 -12 N/m2
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 positively charged particles, each carrying a charge of 3.6 × 10−8 C and having the same mass, are located at a distance of 0.1 m away from each other. If the electrostatic force on one of the charges is equal to its weight, then the mass of the system is :
1.019 g
1.182 g
0.854 g
0.238 g
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
There are three charges, , placed along a straight line of length 10 m, as shown in the given figure.
What is the net electrostatic force acting on charge q2?
12 × 10−3 N towards q1
28.5 × 10−3 N towards q1
12 × 10−3 N towards q3
28.5 × 10−3 N towards q3
A positive charge q is placed at the centre of a cube. A side of the cube is 0.2 m. The electric flux through each Gaussian surface of the cube is 4.708 × 104 N m2 C−1. What is the value of charge q ?
1 μC
1.5 μC
2.5 μC
3 μC
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
Three charges are placed at the vertices of an equilateral triangle of side 0.2 m, as shown in the given figure. What is the magnitude of the net Coulomb force acting on charge q1 due to the other two charges?
2.26 N
3.92 N
4.52 N
7.47 N
