Several light bulbs, each of resistance 1.5 Ω, are connected in a series across a 120 V source of emf. If the current through the circuit is 2 A, how many light bulbs are there in the circuit?

R=V/I=120/2=60 ohms total.

number bulbs= 60/1.5

That is a lot of bulbs.

seat 27

To find the number of light bulbs in the circuit, we need to apply Ohm's Law which states that V = I x R, where V is the voltage, I is the current, and R is the resistance.

In this case, we have:
V = 120 V (given)
I = 2 A (given)
R = 1.5 Ω (resistance of each light bulb)

Since the light bulbs are connected in a series, the total resistance of the circuit is equal to the sum of individual resistances.

Let's start by calculating the total resistance of the circuit:

Total Resistance = R1 + R2 + R3 + ... + Rn

Since all the light bulbs have the same resistance of 1.5 Ω, the equation becomes:

Total Resistance = 1.5 Ω + 1.5 Ω + 1.5 Ω + ... + 1.5 Ω

Since the light bulbs are connected in a series, the current is the same throughout the circuit. Hence:

I = V / Total Resistance

Now we can plug in the given values and solve for the total resistance:

2 A = 120 V / Total Resistance

Rearranging the equation, we get:

Total Resistance = 120 V / 2 A

Total Resistance = 60 Ω

Now, we can find the number of light bulbs by dividing the total resistance by the resistance of each light bulb (1.5 Ω):

Number of light bulbs = Total Resistance / Resistance per light bulb

Number of light bulbs = 60 Ω / 1.5 Ω

Number of light bulbs = 40

Therefore, there are 40 light bulbs in the circuit.

To determine the number of light bulbs in the circuit, we need to use Ohm's Law and the formula for calculating resistance in a series circuit.

Ohm's Law states that V = I * R, where V is the voltage, I is the current, and R is the resistance.

In a series circuit, the total resistance (R_total) is the sum of the resistances of each component in the circuit. Therefore, for a series circuit with n components, R_total = R1 + R2 + R3 + ... + Rn.

In this case, we know the voltage (V = 120 V), the current (I = 2 A), and the resistance of each light bulb (R = 1.5 Ω). We can use Ohm's Law to calculate the total resistance of the circuit:

V = I * R_total
120 V = 2 A * R_total

To find R_total, we rearrange the equation:
R_total = 120 V / 2 A
R_total = 60 Ω

Now that we know the total resistance of the circuit, we can determine the number of light bulbs. Since each light bulb has a resistance of 1.5 Ω, we divide the total resistance by the resistance of each bulb:

Number of light bulbs = R_total / R
Number of light bulbs = 60 Ω / 1.5 Ω
Number of light bulbs = 40

Therefore, there are 40 light bulbs in the circuit.