Explanation:
The total resistance used to calculate the total resistance of the two parallel resistor is given by :
Taking reciprocal of the above equation.
We can also write the above equation as :
On simplification of above equation,
or
Hence, proved.
The formula for accelerational displacement is at^2/2, so we know that 3.9t^2/2 = 200, or 3.9t^2 = 400. t =
, at = v, so
Answer:
scalar quantity
Explanation:
Vector quantities have two characteristics, a magnitude and a direction. Scalar quantities have only a magnitude.
Answer:
0.25 gram of neptunium is remaining
Explanation:
First we calculate the no. of half lives passed. For that we have formula:
n = t/T
where,
n = no. of half lives passed = ?
t = total time passed = 8 days (From Monday noon to Tuesday noon of following week)
T = Half Life Period = 2 days
Therefore,
n = 8 days/2 days
n = 4
Now, for the remaining mass of neptunium, we use the formula:
m = (mi)/(2)^n
where,
mi = initial mass of neptunium = 4.00 grams
m = remaining mass of neptunium = ?
Therefore,
m = 4 grams/2⁴
<u>m = 0.25 gram</u>
<u>Out of all given choices, the following statements are true:</u>
- An ammeter is used to measure current.
- A voltmeter is used to measure voltage.
- A voltmeter must be placed in parallel with a resistor to measure the voltage across the resistor.
Options A, E, and F
<u>Explanation:</u>
An instrument by which the current in a circuit is measured is called ammeter whereas an instrument in which voltage is measured in a circuit is called a voltmeter . The ammeter is placed in series with the resistor while the voltmeter is placed in parallel with the resistor.
For the option B, since the ammeter must be placed in series with the resistor to measure current, it is false. Option C is false because an ammeter has zero internal resistance. Option D is also false because a voltmeter has a high internal resistance and is actually infinite.
