PREPARATORY CLASS EXAMINATION FOR MIDTERM – 2013
(16 Aug 2013)
Candidates are allowed additional 15 minutes for only reading the paper.
They must not start writing during this time
Answer all questions in Part I and eight questions in Part II, choosing two questions from each of the three sections A, B and C.
All working including rough work should be done on the same sheet as, and adjacent to, the rest of the answer.
The intended marks for questions or parts of questions are given in brackets [ ].
Question 1 [ Objective ]
Total 10 marks
Each sub-question carries 1 mark. Answer all.
Which of the following is a vector?
A. An electric dipole’s electric potential
B. An electric dipole’s charge
C. Electric current D. Electric current density
Pick only the correct one “between an electron and a positron”
A. The electron has more specific charge
B. The positron has more specific charge
C. Both have equal specific charge
D. For some particles specific charge can’t be determined, so it can’t be said electron or positron has more specific charge
Chose the correct one
A. Kirchhoff’s loop rule is applied to a junction of incoming and outgoing current
B. According to Kirchhoff’s loop rule a junction of incoming and outgoing current carries a potential proportional to the amount of current flowing through the junction
C. Kirchhoff’s Junction rule can be applied to a single current carrying path in any electric circuit
D. The potential drop in a loop in any electric circuit is zero and its based on conservation of energy
Chose the correct one
A. Resultant of capacitance in series in more than individual resistances
B. Current division works on the basis of direct proportionality of resistances
C. Voltage division works on the basis of direct proportionality of resistances
D. Resistors in series will add up
Total 50 marks (Optional, 6 out of 9. Compulsory 2)
This question is compulsory ( total 7 )
Define electric current and electric current density. State if these two quantities are scalar or vector quantities and explain why. State and explain Ohm’s law. Derive the Ohm’s law in vector form from the scalar form. Write the expression for drift velocity.