Daily review: Ohm’s Law | Relay Quiz Practice Quiz…

Q: What is the unit of measurement for electrical resistance?

Ohm (?) — Resistance is measured in Ohms, named after Georg Ohm.

Q: According to Ohm's Law, if the voltage across a resistor is doubled, the current will:

Double — Current is directly proportional to voltage (I = V/R).

Q: Which of the following is the correct formula for Ohm's Law?

V = I * R — Voltage equals current multiplied by resistance.

Q: What component is primarily used as a switching device controlled by an electrical signal?

Relay — Relays use an electromagnet to open or close a switch.

Q: A relay's coil resistance is 100 ohms. It operates at 12V. What is the current flowing through the coil?

0.12 A — Using Ohm's Law (I = V/R), I = 12V/100? = 0.12A.

Q: What is the function of a relay's normally open (NO) contact?

Closed when the coil is energized — NO contacts are open until the relay coil is energized.

Q: Which of these is NOT a typical application of a relay?

Amplifying current — Relays act as switches, not amplifiers.

Q: What does 'NC' stand for in relation to a relay?

Normally Closed — NC contacts are closed when the relay coil is de-energized.

Q: If a 10-ohm resistor has a current of 2 amps flowing through it, what is the voltage drop across the resistor?

20 V — Using Ohm's Law (V = I*R), V=2A * 10? = 20V.

Q: A relay with a 5V coil voltage has a coil resistance of 250 ohms. What is the power consumed by the relay coil?

0.1 W — Calculate current: I = V/R = 5/250 = 0.02A. Then P=V*I = 5V * 0.02A = 0.1W

Question 1 of 10

What is the unit of measurement for electrical resistance?

Resistance is measured in Ohms, named after Georg Ohm.

Question 2 of 10

According to Ohm's Law, if the voltage across a resistor is doubled, the current will:

Current is directly proportional to voltage (I = V/R).

Question 3 of 10

Which of the following is the correct formula for Ohm's Law?

Voltage equals current multiplied by resistance.

Question 4 of 10

What component is primarily used as a switching device controlled by an electrical signal?

Relays use an electromagnet to open or close a switch.

Question 5 of 10

A relay's coil resistance is 100 ohms. It operates at 12V. What is the current flowing through the coil?

Using Ohm's Law (I = V/R), I = 12V/100? = 0.12A.

Question 6 of 10

What is the function of a relay's normally open (NO) contact?

NO contacts are open until the relay coil is energized.

Question 7 of 10

Which of these is NOT a typical application of a relay?

Relays act as switches, not amplifiers.

Question 8 of 10

What does 'NC' stand for in relation to a relay?

NC contacts are closed when the relay coil is de-energized.

Question 9 of 10

If a 10-ohm resistor has a current of 2 amps flowing through it, what is the voltage drop across the resistor?

Using Ohm's Law (V = I*R), V=2A * 10? = 20V.

Question 10 of 10

A relay with a 5V coil voltage has a coil resistance of 250 ohms. What is the power consumed by the relay coil?

Calculate current: I = V/R = 5/250 = 0.02A. Then P=V*I = 5V * 0.02A = 0.1W

Daily review: Ohm’s Law | Relay Quiz