1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
kirill [66]
3 years ago
13

Two bulbs are connected in parallel across a source of EMF = 8.0V with a negligible internal resistance. One bulb has a resistan

ce of 3.0Ω , and the other is 2.5Ω . A resistor R is connected in the circuit in series with the two bulbs.
(a) What value of R should be chosen in order to supply each bulb with a voltage of 2.4 V?
(b) For what value of R would the potential difference across each of the bulbs be 2.4 V?
Physics
1 answer:
Sonja [21]3 years ago
3 0
<h2>Answer:</h2>

(a) 3.18Ω

(b) 3.18Ω

<h2>Explanation:</h2>

Let the two bulbs be A and B

Given;

R_{A} = Resistance in bulb A = 3.0Ω

R_{B} = Resistance in bulb B = 2.5Ω

Since the two bulbs are connected in parallel;

i. their effective resistance (R_{X}) is given by

\frac{1}{R_{X}} = \frac{1}{R_{A} } + \frac{1}{R_{B} }  ---------------(i)

Substitute the values of R_{A} and R_{B} into equation (i)

=> \frac{1}{R_{X}} = \frac{1}{3.0} + \frac{1}{2.5}

Solve for  R_{X}

R_{X} = 1.36Ω

ii. voltage (potential difference), V, across them is the same;

Therefore we can get the total current (I) that will flow through them if the voltage to be supplied is 2.4V.

Use the Ohm's law;

V = I x R    -----------------(ii)

Where;

V = voltage across them = 2.4V

I = total current flowing through them

R = their effective resistance = R_{X} = 1.36Ω

Substitute these values into equation (ii) as follows;

2.4  = I x 1.36

I = 2.4 / 1.36

I = 1.76A

(a) Now get the value of R

Since the voltage across the two bulbs is 2.4V out of the 8.0V supplied by the source, then the remaining (8.0 - 2.4 = 5.6)V will pass across the resistor R.

Also, since the two bulbs make a series connection with the resistor R, the same total current (I = 1.76A) that flows through these bulbs will flow through the resistor R.

Therefore, to get the value of R, we use the relation

V = I x R   ------------------------------(iii)

Where;

V = voltage across the resistor = 5.6V

I = current through the resistor = 1.76A

<em>Substitute these values into equation (iii)</em>

=> 5.6 = 1.76 x R

=> R  = 5.6 / 1.76

=> R = 3.18Ω

Therefore, the value of R to be chosen in order to supply each bulb with a voltage of 2.4V is 3.18Ω

(b) The potential difference and voltage across refer to the same thing. Therefore, the value of R that would make the potential difference across each of the bulbs be 2.4V is the same as the one calculated in (a) which is 3.18Ω

You might be interested in
Between a plate and the body of a bolt, the projected area is equal to the product of the bolt _______ and the plate _______.
Elan Coil [88]

Answer:

Projected area= Diameter of the bolt* thickness.

Explanation:

Between a plate and the body of a bolt, the projected area is equal to the product of the bolt _Diameter of the bolt______ and the plate ___thickness____.

Projected area= Diameter of the bolt* thickness.

Projected area is a 2-dimensional area measurement of a 3-dimensional body by projecting its surface on an arbitrary plane

8 0
2 years ago
How long can you keep string cheese in the fridge?
allsm [11]
Cheese attributes its sour taste because of its lactic acid content. However, this should not be an indication to whether the cheese is spoiling already. We can tell its expiry date through the manufacturing details of the product. The product should be good to consume before the manufacturing expiry date. Every package must include expiry date in order to inform the consumer about the range of its consumability attributes. In the case where molds are present on the cheese already, cheese on some parts may not be edible already. Molds are due to the oxidation of glucose through the action of specific bacteria.
8 0
3 years ago
Two loudspeakers emit sound waves along the x-axis. A listener in front of both speakers hears a maximum sound intensity when sp
grandymaker [24]

Answer:

frequency of the sound = f = 1,030.3 Hz

phase difference = Φ = 229.09°

Explanation:

Step 1: Given data:

Xini = 0.540m

Xfin = 0.870m

v = 340m/s

Step 2: frequency of the sound (f)

f = v / λ

λ = Xfin - Xini = 0.870 - 0.540 = 0.33

f = 340 / 0.33

f = 1,030.3 Hz

Step 3: phase difference

phase difference = Φ

Φ = (2π/λ)*(Xini - λ) = (2π/0.33)* (0.540-0.33) = 19.04*0.21 = 3.9984

Φ = 3.9984 rad * (360°/2π rad)

Φ = 229.09°

Hope this helps!

5 0
3 years ago
5. The disks, or pads, that exist between bones as gliding joints are made of which substance?
DerKrebs [107]

Answer:

cartilage

Explanation:

5 0
3 years ago
The fraction of the total radiation that is reflected by any surface is called its _____.
Vadim26 [7]

Answer: D. Albedo

Explanation:

The proportion of total light incident on surface that is reflected back is called its albedo. These are typical features of an astronomical body. It is a dimension less quantity and its value ranges from 0 to 1. Light surfaces reflect larger amount of light than dark surfaces. This feature can be clearly seen on planet Mars and the Moon.

Thus, the fraction of the total radiation that is reflected by any surface is called its <u>Albedo.</u>

8 0
3 years ago
Read 2 more answers
Other questions:
  • Two charged spheres are 8.45 cm apart. They are moved, and the force on each of them is found to have been tripled. How far apar
    10·1 answer
  • Some help please ,.......
    13·2 answers
  • How does acceleration affect speed and velocity
    11·1 answer
  • The umbra during a SOLAR OR LUNAR eclipse is smaller than during a SOLAR OR LUNAR eclipse.
    12·1 answer
  • The Statue of Liberty weighs nearly 205 metric tons. If a person can pull an average of 90 kg, how many people would it take to
    12·1 answer
  • Which property of gases best explains the ability of air bags to cushion the force of impact during a car accident?
    10·1 answer
  • Tomorrow i have a science test, could someone please fill me in on the water cycle?
    12·1 answer
  • TRUE of FALSE: The human body responds to stressors by activating the nervous
    5·1 answer
  • Two loudspeakers emit sound waves along the x-axis. The sound has maximum intensity when the speakers are 20 cm apart. The sound
    15·1 answer
  • Dharna is said to be concentration it is true or false​
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!