Grade 8 Science

Question 1

What is Ohm’s law?

Answer 1

Ohm’s law states that the current through a conductor between two points is directly proportional to the voltage across the two points.

Question 2

What is the formula for Ohm’s law?

Answer 2

The formula for Ohm’s law is V = I * R, where V is the voltage, I is the current, and R is the resistance.

Question 3

What is the unit of resistance?

Answer 3

The unit of resistance is the ohm, symbolized by the Greek letter omega (Ω).

Question 4

True or False: Resistance is the opposition to the flow of electric current.

Answer 4

True

Question 5

What happens to current if resistance increases in a circuit?

Answer 5

If resistance increases in a circuit, the current decreases.

Question 6

Fill in the blank: According to Ohm’s law, current is proportional to ________.

Answer 6

voltage

Question 7

What is the relationship between voltage and current in a circuit according to Ohm’s law?

Answer 7

Voltage and current are directly proportional in a circuit according to Ohm’s law.

Question 8

If the voltage in a circuit is 12 volts and the resistance is 4 ohms, what is the current flowing through the circuit?

Answer 8

The current flowing through the circuit is 3 amperes.

Question 9

What is the SI unit of current?

Answer 9

The SI unit of current is the ampere.

Question 10

What is the relationship between resistance and current in a circuit according to Ohm’s law?

Answer 10

Resistance and current are inversely proportional in a circuit according to Ohm’s law.

Question 11

What happens to current if voltage increases in a circuit?

Answer 11

If voltage increases in a circuit, the current also increases.

Question 12

What is the formula for calculating resistance using Ohm’s law?

Answer 12

The formula for calculating resistance using Ohm’s law is R = V / I, where R is the resistance, V is the voltage, and I is the current.

Question 13

Fill in the blank: According to Ohm’s law, resistance is inversely proportional to ________.

Answer 13

current

Question 14

What is the relationship between voltage and resistance in a circuit according to Ohm’s law?

Answer 14

Voltage and resistance are directly proportional in a circuit according to Ohm’s law.

Question 15

If the current in a circuit is 5 amperes and the resistance is 10 ohms, what is the voltage across the circuit?

Answer 15

The voltage across the circuit is 50 volts.

Question 16

True or False: Ohm’s law is only applicable to resistive circuits.

Answer 16

False

Question 17

What is the relationship between power, current, and voltage in a circuit?

Answer 17

The relationship between power, current, and voltage in a circuit is given by the formula P = V * I, where P is power, V is voltage, and I is current.

Question 18

What is the formula for calculating power in a circuit?

Answer 18

The formula for calculating power in a circuit is P = V * I, where P is power, V is voltage, and I is current.

Question 19

What is the SI unit of power?

Answer 19

The SI unit of power is the watt.

Question 20

If the voltage in a circuit is 24 volts and the current is 6 amperes, what is the power consumed by the circuit?

Answer 20

The power consumed by the circuit is 144 watts.

Question 21

Fill in the blank: Power is the rate at which ________ is done in a circuit.

Answer 21

work

Question 22

True or False: Power dissipation in a circuit is independent of resistance.

Answer 22

False

Question 23

What is the formula for calculating power dissipation in a circuit with resistance?

Answer 23

The formula for calculating power dissipation in a circuit with resistance is P = I^2 * R, where P is power, I is current, and R is resistance.

Question 24

If the current in a circuit is 2 amperes and the resistance is 5 ohms, what is the power dissipation in the circuit?

Answer 24

The power dissipation in the circuit is 20 watts.