Related InterviewSolutions

• The small identical conducting spheres have charges of 2.0 × 10−9 C and − 0.5 × 10−9 respectively. When they are placed 4 cm apart, what is the force between them ? If they are brought into contact and then separated by 4 cm, what is the force between them ? 
• If D is the electric flux density, then value of electric intensity in air is (a) D/ε0 (b) D/ε0εr(c) dV/dt (d) Q/εA
• For any medium, electric flux density D is related to electric intensity E by the equation (a) D = ε0E (b) D = ε0εrE (c) D = E/ε0εr (d) D = ε0E/εr
• Inside a conducting sphere,...remains constant (a) electric flux (b) electric intensity (c) charge (d) potential
• According to Gauss’s theorem, the surface integral of the normal component of electric flux density D over a closed surface containing charge Q is (a) Q (b) Q/ε0 (c) ε0Q (d) Q2/ε0
• Capacitance (in F) of a spherical conductor with radius 1 m is(a) 1.1 × 10–10 (b) 10–6(c) 9 × 10–9 (d) 10–3 .
• Electric flux emanating from an electric charge of + Q coulomb is (a) Q/ε0 (b) Q/εr (c) Q/ε0εr (d) Q
• Two similar electric charges of 1 C each are placed 1 m apart in air. Force of repulsion between them would be nearly...... newton (a) 1 (b) 9 × 109 (c) 4 π (d) 8.854 × 10−12
• A parallel-plate capacitor consists of two square metal plates 500 mm on a side separated by 10 mm. A slab of Teflon (εr = 2.0) 6 mm thick is placed on the lower plate leaving an air gap 4 mm thick between it and the upper plate. If 100 V is applied across the capacitor, find the electric field (E0) in the air, electric field Et in Teflon, flux density Da in air, flux density Dt in Teflon and potential difference Vt across Teflon slab.
• The unit of absolute permittivity of a medium is (a) joule/coulomb (b) newton-metre (c) farad/metere (d) farad/coulomb