Ask question

Ask question

All categories

3 years ago

6

Horace has invented a unique pair of reading glasses that have two small light bulbs at the bottom wired in series, so that he c

an see the newspaper when he is reading at night. Each of the bulbs has a resistance of 2.00 , and the system runs off a 3.20-V battery. How much current is drawn by Horace’s reading glasses?

1 answer:

ElenaW [278]3 years ago

3 0

Answer:

The current drawn by Horace’s reading glasses is 0.8 A.

Explanation:

Given that,

Resistance of each bulb, R = 2 ohms

Voltage of the system, V = 3.2 volts

These two bulbs are connected in series. The equivalent resistance will be 2 ohms +2 ohms = 4 ohms

Let I is the current drawn by Horace’s reading glasses. Using Ohm's law to find it such that :

$V=IR\\\\I=\dfrac{V}{R}\\\\I=\dfrac{3.2}{4}\\\\I=0.8\ A$

So, the current drawn by Horace’s reading glasses is 0.8 A.

You might be interested in

As an object sinks in a fluid, the buoyant force ____.

kiruha [24]

Beginning when the bottom of the object first touches the water,
and as it descends and more and more of it goes under, the
buoyant force on it increases during that time.

As soon as the object is completely underwater, it doesn't matter
how deep under it is, the buoyant force on it remains the same.

3 0

3 years ago

Read 2 more answers

A piston-cylinder device contains Helium gas initially at 150 kPa, 20 o C, and 0.5m 3 . The helium is now compressed in a polytr

Molodets [167]

Answer:

Explanation:

Given

$P_1=150 kPa$

$T_1=20^{\circ}C$

$V_1=0.5 m^3$

$T_2=140^{\circ}C$

$P_2=400 kPa$

R for Helium $R=2.076$

$c_v=3.115 kJ/kg-K$

mass of gas $m=\frac{P_1V_1}{RT_1}$

$m=\frac{150\times 0.5}{2.076\times 293}$

$m=0.123 kg$

Similarly $V_2$ can be found

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

$V_2=0.264 m^3$

Work done $W=\int_{V_1}^{V_2}PdV$

$W=\frac{P_2V_2-P_1V_1}{n-1}$

$W=\frac{mR(T_2_T_1)}{n-1}$

Since it is a polytropic Process

therefore $PV^n=c$

$P_1V_1^n=P_2V_2^n$

$(\frac{V_1}{V_2})^n=\frac{P_2}{P_1}$

$(\frac{0.5}{0.264})^n=\frac{400}{150}$

$n=\frac{\ln 2.66}{\ln 1.893}$

$n=1.533$

$W=\frac{0.123\times 2.076(140-20)}{1.533-1}$

$W=57.48 kJ$

From Energy balance

$E_{in}-E_{out}=\Delta E_{system}$

Neglecting kinetic and Potential Energy change

$Q_{in}+W_{in}=change\ in\ Internal\ Energy$

Change in Internal Energy $\Delta U=u_2-u_1$

$\Delta U=mc_v(T_2-T_1)$

$\Delta U=0.123\times 3.115(140-20)$

$\Delta U=45.977 kJ$

$Q_{in}+57.48=45.977$

$Q_{in}=-11.50 kJ$

i.e. Heat is being removed

3 0

3 years ago

Which statement supports Newton’s first law of motion?

Ipatiy [6.2K]

Answer: The statement that supports Newton's first law of motion is the one that says that planets can move at a varying speed due to forces exerted in space

6 0

2 years ago

Read 2 more answers

Which best explains why a satellite accelerates?

Gnoma [55]

A) it is always changing direction

4 0

3 years ago

Read 2 more answers

HELP PLZZZZZZZZZZZZZZZ ASAP!!!

WINSTONCH [101]

Electromagnetic waves..............................

3 0

2 years ago