ISCET DC Circuits Fundamentals 4

Question 1

A wire carries 5A of current. How many coulombs of charge pass a point in 30 seconds?

Accepted Answer

150 C

Answer

Q = I × t = 5A × 30s = 150 coulombs.

Question 2

Which statement correctly describes the relationship between EMF and terminal voltage of a battery under load?

Accepted Answer

Terminal voltage is less than EMF due to internal resistance drop

Answer

Under load, current through internal resistance causes a voltage drop, making terminal voltage = EMF − I×r.

Question 3

Two 60Ω resistors connected in series are then placed in parallel with a 40Ω resistor. What is the total resistance?

Accepted Answer

30Ω

Answer

Series pair = 60+60 = 120Ω; parallel with 40Ω gives Req = (120×40)/(120+40) = 4800/160 = 30Ω.

Question 4

What does the term 'short circuit' mean in a DC circuit?

Accepted Answer

A path of near-zero resistance bypassing the load

Answer

A short circuit is an unintended low-resistance connection that allows excessive current to bypass the intended load.

Question 5

Resistivity of a conductor depends on which factors?

Accepted Answer

Material type and temperature

Answer

Resistivity (ρ) is an intrinsic property of the material that changes with temperature, not with the physical dimensions of the conductor.

(ISCET) International Society of Certified Electronics Technicians Practice Test