NYC Radio Repair Mechanic Exam ACTUAL EXAM
COMPLETE QUESTIONS AND CORRECT ANSWERS LATEST
UPDATE THIS YEAR
SECTION 1: DC CIRCUIT ANALYSIS
Question 1
A 24V DC source is connected to a 6Ω load. What current flows in the
circuit?
A) 2 A
B) 4 A
C) 6 A
D) 144 A
Correct Answer: B
Rationale: I = V/R = 24/6 = 4 A. Ohm's law is the fundamental
relationship between voltage, current, and resistance in DC circuits
.
Question 2
Two resistors, 47Ω and 33Ω, are connected in series. What is the total
resistance?
,A) 14Ω
B) 80Ω
C) 1.55kΩ
D) 33Ω
Correct Answer: B
Rationale: Series resistances add: 47 + 33 = 80Ω. Only one path
exists for current flow, so resistances are cumulative .
Question 3
Three 30Ω resistors are wired in parallel. What is the equivalent
resistance?
A) 90Ω
B) 30Ω
C) 10Ω
D) 3Ω
Correct Answer: C
Rationale: Parallel formula: 1/Req = 1/30 + 1/30 + 1/30 = 3/30, so
Req = 10Ω. Parallel paths reduce total resistance .
Question 4
A resistor measures 220Ω with a 10% tolerance. What is the acceptable
resistance range?
,A) 198Ω to 242Ω
B) 200Ω to 240Ω
C) 210Ω to 230Ω
D) 220Ω only
Correct Answer: A
Rationale: 10% of 220 = 22Ω. Acceptable range: 220 - 22 = 198Ω to
220 + 22 = 242Ω .
Question 5
In a voltage divider with R1 = 10kΩ and R2 = 5kΩ across a 15V supply, what
is the voltage across R2?
A) 5V
B) 10V
C) 7.5V
D) 15V
Correct Answer: A
Rationale: Vout = Vin × R2/(R1+R2) = 15 × 5k/15k = 5V. The voltage
divider distributes voltage in proportion to resistance .
Question 6
A 9V battery is rated at 500 mAh. Approximately how long can it deliver
50 mA?
, A) 5 hours
B) 10 hours
C) 20 hours
D) 45 hours
Correct Answer: B
Rationale: Time = capacity/current = 500 mAh/50 mA = 10 hours.
This assumes ideal conditions with no voltage sag .
Question 7
What is the total power dissipated by a circuit drawing 2 A at 12 V?
A) 6 W
B) 14 W
C) 24 W
D) 0.167 W
Correct Answer: C
Rationale: P = V × I = 12 × 2 = 24 W. Power is the rate of energy
consumption .
Question 8
A 100Ω resistor has 5 V across it. How much power does it dissipate?
A) 0.05 W
B) 0.25 W
COMPLETE QUESTIONS AND CORRECT ANSWERS LATEST
UPDATE THIS YEAR
SECTION 1: DC CIRCUIT ANALYSIS
Question 1
A 24V DC source is connected to a 6Ω load. What current flows in the
circuit?
A) 2 A
B) 4 A
C) 6 A
D) 144 A
Correct Answer: B
Rationale: I = V/R = 24/6 = 4 A. Ohm's law is the fundamental
relationship between voltage, current, and resistance in DC circuits
.
Question 2
Two resistors, 47Ω and 33Ω, are connected in series. What is the total
resistance?
,A) 14Ω
B) 80Ω
C) 1.55kΩ
D) 33Ω
Correct Answer: B
Rationale: Series resistances add: 47 + 33 = 80Ω. Only one path
exists for current flow, so resistances are cumulative .
Question 3
Three 30Ω resistors are wired in parallel. What is the equivalent
resistance?
A) 90Ω
B) 30Ω
C) 10Ω
D) 3Ω
Correct Answer: C
Rationale: Parallel formula: 1/Req = 1/30 + 1/30 + 1/30 = 3/30, so
Req = 10Ω. Parallel paths reduce total resistance .
Question 4
A resistor measures 220Ω with a 10% tolerance. What is the acceptable
resistance range?
,A) 198Ω to 242Ω
B) 200Ω to 240Ω
C) 210Ω to 230Ω
D) 220Ω only
Correct Answer: A
Rationale: 10% of 220 = 22Ω. Acceptable range: 220 - 22 = 198Ω to
220 + 22 = 242Ω .
Question 5
In a voltage divider with R1 = 10kΩ and R2 = 5kΩ across a 15V supply, what
is the voltage across R2?
A) 5V
B) 10V
C) 7.5V
D) 15V
Correct Answer: A
Rationale: Vout = Vin × R2/(R1+R2) = 15 × 5k/15k = 5V. The voltage
divider distributes voltage in proportion to resistance .
Question 6
A 9V battery is rated at 500 mAh. Approximately how long can it deliver
50 mA?
, A) 5 hours
B) 10 hours
C) 20 hours
D) 45 hours
Correct Answer: B
Rationale: Time = capacity/current = 500 mAh/50 mA = 10 hours.
This assumes ideal conditions with no voltage sag .
Question 7
What is the total power dissipated by a circuit drawing 2 A at 12 V?
A) 6 W
B) 14 W
C) 24 W
D) 0.167 W
Correct Answer: C
Rationale: P = V × I = 12 × 2 = 24 W. Power is the rate of energy
consumption .
Question 8
A 100Ω resistor has 5 V across it. How much power does it dissipate?
A) 0.05 W
B) 0.25 W
