phy204 Posts: 1, Reputation: 1 New Member   #1 May 13, 2012, 04:56 PM

The force per unit charge refers to --------- 1 The force per unit charge refers to --------- electric potential electric current elctric field electromotive force 2 An insulating material is said to be -------- paramagnetic dieletric superconducting semiconducting 3 An electric field has a magnitude of 350N/C and makes an angle of 50o at each point on a flat rectangular horizontal surface of dimensions 20cm by 15cm. Calculate the electric flux for this surface 6 72Nm2 C 1 67Nm2 C 8 23Nm2 C 7 36Nm2 C 4 An electrical device in which two parallel conducting plates are in proximity but separated by an insulating material is called a --------- inductor resistor capacitor semiconductor 5 Two parallel conducting plates of area 100cm-squared in a vacuum are each given equal but opposite charges of 8 9 10−7C . What is the magnitude of the electric field between the plates? Take o=8 85 10−12C2 Nm2 107N C 206N C 303N C 404N C 6 A 2.0F capacitor is desired. What should be the area of the plates if they are to be separated by a 4.5mm air gap? Take o=8 85 10−12C2 Nm2 107m2 205m2 109m2 303m2 7 Capacitance of a capacitor depends on all of the following EXCEPT ------------- potential difference across the capacitor area of the plates of the capacitor distance of one plate from the other electric current through the capacitor 8 Find the charge on a 1000 pF capacitor when charged to a voltage of 24V 0.24 C 0.048 C 0.024 C 0.48 C 9 Calculate the electric field between two plates which are 2cm apart in a vacuum and connected to a 120v battery 2400V/m 6000V/m 3000V/m 4000V/m 10 A 1.2 microfarad capacitor is charged to 3 kV. Calculate the energy stored in the capacitor 5.4J 3.3J 1.7J 12.8J 11 Two identical capacitors are connected in parallel, charged by a battery of voltage V, and then isolated from the battery. One of the capacitors is then filled with a material of relative permittivity K. What is the final potential difference across the plates of the capcitor 2KV 2V/K 2V/(K+1) 2V/(K-1) 12 Which of the following correctly represents the dimensions of dipole moment? [charge] [length] [carge][length] [charge]/[length] 13 A neutral molecule placed in an electric field becomes ------------ discharged ionised polarised charged 14 A molecule in which the centre of the electron cloud does NOT coincide with the cenre of the nuleus is called ----------- molecule dielectric ferromagnetic polar diamagnetic 15 Which of the following statements is correct? polar molecule has induced dipole moment a non-polar molecule has permanent dipole moment a non-polar molecule acquires a dipole moment in the presence of an electric field a polar molecule acquires permanent dipole moment in the presence of an electric field 16 When a rectangular dielectric slab is placed in an electric field, polarisation charges appear on the surfaces of the dielectric perpendicular to the field surface charges appear on the surfaces of the dielectric parallel to the field the induced dipole moment decreases with increase in the field surface density of bound charges does not depend on the shape of the dielectric material 17 The correct dimensions of polarisation is ---------- [charge]/[length] [charge][length] [charge]/[length squared] [charge]/[length cubed] 18 A dielectric material in which the magnitude and direction of the induced dipole momement do not depend on the orientation of the crystal axis with respect to the direction of the external electric field is called --------- dielectric crystalline amorphous anisotropic isotropic 19 A surface element of a dielectric material dS is inclined at an angle A to the direction of the external electric field. Given that the dipole moment per unit volume is P, then surface charge density aqcuired by the material is PdSsinA PdStanA PdScotA PdScosA 20 A device usually used for storing charges in electrical circuits is --------------- inductor capacitor resistor insulator

Reply

phy204

View Public Profile

Find latest posts by phy204

Check out some similar questions!