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3 years ago

A milliammeter has an internal resistance of 5ohms and

Physics

1 answer:

Vikentia [17]3 years ago

7 0

Answer:

Rs = 0.02008 Ω = 20.08 mΩ

Explanation:

The range of an ammeter can be increased by connecting a small shunt resistance to it in a series combination. This shunt resistance can be calculated by the following formula:

$Rs = \frac{I_gR_g}{I - I_g}$

where,

$R_s$ = value of shunt resistance = ?

$I_g$ = current range of ammeter = 20 mA = 0.02 A

I = Required range of ammeter = 5 A

$R_g$ = Resistance of ammeter = 5 ohms

Therefore,

$R_s = \frac{(0.02\ A)(5\ ohms)}{5\ A-0.02\ A}$

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3 years ago

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3 years ago

The three forces shown act on a particle. what is the direction of the resultant of these three forces?

melisa1 [442]

Missing figure: http://d2vlcm61l7u1fs.cloudfront.net/media/f5d/f5d9d0bc-e05f-4cd8-9277-da7cdda3aebf/phpJK1JgJ.png

Solution:
We need to find the magnitude of the resultant on both x- and y-axis.

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3 years ago

A human being can be electrocuted if a current as small as 55 mA passes near the heart. An electrician working with sweaty hands

evablogger [386]

Answer:

The lethal voltage for the electrician under those conditions is 126.5 V.

Explanation:

To discover what is the lethal voltage to the electrician we need to find out what is the voltage that produces 55 mA = 0.055 A when across a resistance of 2300 Ohms (Electrician's body resistancy). For that we'll use Ohm's Law wich is expressed by the following equation:

V = i*R

Where V is the voltage we want to find out, i is the current wich is lethal to the electrician and R is his body resistance. By applying the given values we have:

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The lethal voltage for the electrician under those conditions is 126.5 V.

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3 years ago

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2 years ago