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Sonbull [250]
1 year ago
13

a torch bulb is rated 2.5V and 750mA. Calculate its power,its resistance and the energy consumed if this bulb lighted for 4 hour

s
Physics
1 answer:
Hatshy [7]1 year ago
3 0
Using Ohm's Law, we can derived from this the value of resistance. If I=V/R, therefore, R = V/I
Substituting the values to the given, 
P = Power = ?
R = Resistance = ?
V = Voltage = 2.5 V
I = Current = 750 mA

R = V/I = 2.5/ (750 x 10^-3)
R = 3.33 ohms

Calculating the power, we have P = IV

P = (750 x 10^-3)(2.5) 
P = 1.875 W

The power consumption is the power consumed multiply by the number of hours. In here, we have;
1.875W x 4 hours = 7.5 watt-hours
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lisabon 2012 [21]

As per kinematics equation we are given that

v^2 = v_o^2 + 2ax

now we are given that

a = 2.55 m/s^2

v_0 = 21.8 m/s

v = 0

now we need to find x

from above equation we have

0^2 = 21.8^2 + 2(2.55)x

0 = 475.24 + 5.1 x

x = 93.2 m

so it will cover a distance of 93.2 m

7 0
2 years ago
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A kangaroo jumps to a vertical height of 2.8 m. How long was it in the air before returning to earth
BaLLatris [955]
The answer would be 2.8m height on earth takes 
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8 0
1 year ago
Consider an alcohol and a mercury thermometer that read exactly 0 oC at the ice point and 100 oC at the steam point. The distanc
Alexeev081 [22]

Answer:

No, both the thermometers will give the different reading.

Explanation:

Given,

  • Both thermometer has same ice point = T_i\ =\ 0^o C
  • Both thermometer has same steam point = T_s\ =\ 100^o C
  • Distance between the ice point and steam point in both the thermometer is same of 100 division,

All the data given in both the thermometers are same, but the material in the thermometer is different due to this the reading at 60^o C will differ in both the thermometer. Because the reading on both the thermometer is depended upon the thermal expansion of the material inside it, but both the materials are different. Due to this the rise of fluid in the thermometer, i,e,. the volume of the fluid material in the thermometer will depend upon the thermal expansion.  Hence both the material alcohol and mercury have the different thermal expansion, therefore the rise of the fluid in the thermometer also differ in both the thermometer.

7 0
1 year ago
You have been abducted by aliens and find yourself on a strange planet. Fortunately, you have a meter stick with you. You observ
defon

Answer:

36.4276\ m/s^2

Explanation:

m = Mass of stick

L = Length of stick = 1 m

h = Center of mass of stick = \dfrac{1}{2}=0.5\ m

g = Acceleration due to gravity

T = Time period = 0.85 s

Time period is given by

T=2\pi\sqrt{\dfrac{I}{mgh}}

Moment of inertia is given by

I=m\dfrac{L^2}{3}

T=2\pi\sqrt{\dfrac{m\dfrac{L^2}{3}}{mgh}}\\\Rightarrow T=2\pi\sqrt{\dfrac{L^2}{3gh}}\\\Rightarrow g=\dfrac{4\pi^2L^2}{3hT^2}\\\Rightarrow g=\dfrac{4\pi^2\times 1^2}{3\times 0.5\times 0.85^2}\\\Rightarrow g=36.4276\ m/s^2

The acceleration of gravity on this planet is 36.4276\ m/s^2

0 0
1 year ago
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A housefly walking across a surface may develop a significant electric charge through a process similar to frictional charging.
Umnica [9.8K]

Answer:

Number of electrons, n=3.87\times 10^8\ electrons

Explanation:

Given that,

Charge on the fly, q=62\ pC=62\times 10^{-12}\ C

Let n is the number of electrons lose to the surface it is walking across. It is case of quantization of electric charge. It is given by :

q=ne

n=\dfrac{q}{e}

n=\dfrac{62\times 10^{-12}}{1.6\times 10^{-19}}

n = 387500000 electrons

or

n=3.87\times 10^8\ electrons

So, there are 3.87\times 10^8 electrons. Hence, this is the required solution.

3 0
1 year ago
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