Assignment 1
EE105: Linear Circuit Analysis 1
Lecture 1: Basic Concepts
Assigned on: September 4, 2019
Due Date: September 11, 2019
1. How many coulombs are represented by these amounts of electrons?
(a) 6.482x1017
(c) 2.46x1019
18
(b) 1.24x10
(d) 6.628x10
2. A current of 3.1 A flows through a conductor. Calculate how many charge passes through any crosssection of the conductor in 20s.
3. The charge entering element is shown in Fig. 1.23. Find the current at:
(a) t = 1ms
(b) t = 6ms
(c) t = 10ms
4. The current flowing past a point in a device is shown in Fig. 1.25. Calculate the total charge through
the point
5. The current through an element is shown in Fig. 1.26. Determine the total charge that passed through
the element at:
(a) t = 1s
(b) t = 3s
(c) t = 5s
6. A rechargeable flash-light battery is capable of delivering 85 mA for about 12 h. How much charge
can it release at that rate? If its terminal voltage is 1.2 V, how much energy can the battery deliver?
7. The voltage v across a device and the current I through it are
vt   5 cos 2t V,


it   10 1  e0.5t A
Calculate:
(a) The total charge in the device at t = 1s
(b) The power consumed by the device at t = 1s.
8. A 60-W incandescent bulb operates at 120 V. How many electrons and coulombs flow through the
bulb in one day?
9. A 1.8-kW electric heater takes 15 min to boil a quantity of water. If this is done once a day and power
costs 10 cents/kWh, what is the cost of its operation for 30 days?
10. A 30 W luminescent lamp is connected to a 120 V source and is left burning continuously in an
otherwise dark staircase. Determine:
(a) The current through the lamp
(b) The cost of operating the light for one non-leap year if electricity costs 12 rupee per kWh.
Note:
Use paper A4, other than the size of paper will be deducted the grade 10%