Physics

PHYSICS; ELECTROSTATICS MAXIMUM MARKS 70 TIME 1:30 HRS 1) SI unit of permittivity of free space is a) CN -1M-1 b) NM2C-2 c) C2N-1M-2 d) C2N-2M-2 2) Number of electrons present in 1 coulomb of charge is a) 6.25x1018 b) 6.25x1019 c) 6.25x1020 6.023x1023 6 3) The voltage of a cloud is 4x10 v with respect to ground. In a lightening stroke 4 coulomb charge is transferred to the ground in 0.1 second. Power of the lightening stroke is a) 160 watt b) 80 watt c) 20 watt d) 500 watt 4) Electric potential due to uniformly charged conducting sphere with distance is plotted as a) b) c) d)

5) φ1flux is entering in a cubical region and φ2 flux is coming out of a cubical region . Charge enclosed within the cubical region is a) (φ1 - φ2 ) / ϵ 0 d) (φ2 – φ1 ) ϵ 0 b) (φ2 – φ1 ) / ϵ 0 c) φ1 - φ2 ) / 6 ϵ 0 6) Capacitance of a spherical capacitor of radius 1 m is a) 1.1x10-11 F b)10-6 F c) 9x10-9 F d)10-3 F 7)A charged capacitor of capacitance C1 is connected with an uncharged capacitor C2 then equivalent capacitance a) Potential V= C1 C2 /( C1 + C2 ) b) Energy U= C12v12 /( C1 + C2 ) c) Loss of Energy ΔU= C1 C2 v2 / ( C1 + C2 ) d) None 8) Find the true statementa) When charged particle is placed near a metallic conductor it becomes charged. b) Electric field near the surface of the conductor is always normal to the surface c) Electric field and potential due to a point charge decreases with increase of the distance 9) The equivalent capacitance f given capacitor resistor network is a) C b) 3C c) C/3 d) None 10) Electric field in the region is proportional to 1/R3 a) The system is a point charge b) Electric dipole c) pair of point charges d) multiple charges