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
VashaNatasha [74]
3 years ago
7

An electric heater containing two heating wires X and Y is connected to a power supply of electromotive force(emf) 9.0V and negl

igible internal resistance as shown in fig 6.1
Wire X has a resistance of 2.4 ohm and wire Y has a resistance of 1.2ohm. A voltmeter is connected in parallel with the wires. A variable resistor is used to adjust the power dissipated in wires X and Y.

The variable resistor is adjusted so that the voltmeter reads 6.0V.

Calculate the resistance of the variable resistor. ​

Physics
1 answer:
mina [271]3 years ago
7 0

Answer:

0.4 ohms.

Explanation:

From the circuit,

The voltage reading in the voltmeter = voltage drop across each of the parallel resistance.

1/R' = 1/R1+1/R2

R' = (R1×R2)/(R1+R2)

R' = (2.4×1.2)/(2.4+1.2)

R' = 2.88/3.6

R' = 0.8 ohms.

Hence the current flowing through the circuit is

I = V'/R'................ Equation 1

Where V' = voltmeter reading

I = 6/0.8

I = 7.5 A

This is the same current that flows through the variable resistor.

Voltage drop across the variable resistor = 9-6 = 3 V

Therefore, the resistance of the variable resistor = 3/7.5

Resistance = 0.4 ohms.

You might be interested in
The mass of block B is twice the mass of block A, while the mass of the pulley is equal to the mass of block A. The blocks are l
marshall27 [118]

Answer:

C)the right cord pulls on the pulley with greater force than the left cord

Explanation:

As we can see the figure that B is connected to the right string while A is connected to the left string

Now force equation for B as it will move downwards is given as

(2m)g - T_B = (2m)a

similarly for block A which will move upwards we can write the equation as

T_A - mg = ma

now we know that pulley is also rotating so the tangential acceleration of the rope at the contact point with pulley must be same as that of acceleration of the blocks

so here pulley will rotate clockwise direction

So tension in the right string must be more than the left string

So correct answer will be

C)the right cord pulls on the pulley with greater force than the left cord

3 0
3 years ago
A steel bridge is 1000 m long at -20°C in winter. What is the change in length when the temperature rises to 40°C in summer? The
xenn [34]

Answer:

ΔL = 0.66 m

Explanation:

The change in length on an object due to rise in temperature is given by the following equation of linear thermal expansion:

ΔL = αLΔT

where,

ΔL = Change in Length of the bridge = ?

α = Coefficient of linear thermal expansion = 11 x 10⁻⁶ °C⁻¹

L = Original Length of the Bridge = 1000 m

ΔT = Change in Temperature =  Final Temperature - Initial Temperature

ΔT = 40°C - (-20°C) = 60°C

Therefore,

ΔL = (11 x 10⁻⁶ °C⁻¹)(1000 m)(60°C)

<u>ΔL = 0.66 m</u>

6 0
4 years ago
If the Earth was the size of a basketball, about 24 centimeters in diameter, about how thick is the Earth's crust?
zalisa [80]
C)yea there you go hope that helped
4 0
3 years ago
What is the next step if the data from an investigation do not support the original hypothesis? A. The data are revised to suppo
Leno4ka [110]
I believe the answer is D. <span>The hypothesis is revised and another experiment is conducted.</span>
5 0
4 years ago
Read 2 more answers
The sphere that refers to Earths water is called the
soldier1979 [14.2K]
Earth Spheres. Earth's Spheres. Everything in Earth's system can be placed into one of four major subsystems: land, water, living things, or air. These four subsystems are called “spheres.” Specifically, they are the lithosphere (land), hydrosphere (water), biosphere (living things), and atmosphere (air).
6 0
3 years ago
Read 2 more answers
Other questions:
  • The absence of any mechanical linkage between the throttle pedal and the throttle body requires the use of a _______ motor.
    8·1 answer
  • In the Bohr model of the hydrogen atom, an electron moves in a circular path around a proton. The speed of the electron is appro
    9·1 answer
  • a plane flying due east at 395 km/h, is hit by wind blowing at 55 km/h toward the west. what is the resultant velocity of the pl
    6·2 answers
  • Little Susie is enjoying a nice spherical lollipop. She sucks the lollipop in such away that the circumference decreases by 1 ce
    15·1 answer
  • A 5 m3 tank containing 5kg of an unknown ideal gas at 500 kPa is connected through a valve to another tank containing 10 kg of t
    14·1 answer
  • Describe how the potential energy changes
    8·2 answers
  • A dragster and driver together have mass 942.9 kg . The dragster, starting from rest, attains a speed of 26.3 m/s in 0.61 s. Fin
    13·1 answer
  • Tell me what the
    15·1 answer
  • 37. Which body exerts the strongest gravitational force on you?
    12·2 answers
  • 100 POINTS+BRAINLIEST: 8TH GRADE PHYSICS: “As an object moves away from the center of the earth, the force of gravity INCREASES
    8·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!