PYQSidePowered by
ExamsMy practice
Two charges of 5Q and -2Q are situated at the points (3a,0) and (-5a,0) respectively. The electric flux through a sphere of radius '4a' having center at origin is :
(4) 5Q 0
[figure]
= qenc 0 (Gauss's law)
5Q at distance 3a<4a: inside
-2Q at distance 5a>4a: outside
only enclosed charge gives net flux through a closed surface.
= 5Q 0
Answer: (4)
An electron is moving under the influence of the electric field of a uniformly charged infinite plane sheet S having surface charge density + . The electron at t=0 is at a distance of 1 m from S and has a speed of 1 m/s. The maximum value of if the electron strikes S at t=1 s is [ m 0e ] Cm2, the value of is .
An electric field is given by (6 i+5 j+3 k) N/C. The electric flux through a surface area 30 i m2 lying in YZ-plane (in SI unit) is :
A thin metallic wire having cross sectional area of 10-4 m2 is used to make a ring of radius 30 cm. A positive charge of 2 C is uniformly distributed over the ring, while another positive charge of 30 pC is kept at the centre of the ring. The tension in the ring is N; provided that the ring does not get deformed (neglect the influence of gravity). (given, 14 0 = 9 109 SI units)
Two charges of -4 and +4 are placed at the points A(1, 0, 4) m and B(2, -1, 5) m located in an electric field E=0.20 i V/cm. The magnitude of the torque acting on the dipole is 8 10-5 Nm, where = .