Answer:
The resistance of the tungsten coil at 80 degrees Celsius is 15.12 ohm
Explanation:
The given parameters are;
The resistance of the tungsten coil at 15 degrees Celsius = 12 ohm
The temperature coefficient of resistance of tungsten = 0.004/°C
The resistance of the tungsten coil at 80 degrees Celsius is found using the following relation;
R₂ = R₁·[1 + α·(t₂ - t₁)]
Where;
R₁ = The resistance at the initial temperature = 12 ohm
R₂ = The resistance of tungsten at the final temperature
t₁ = The initial temperature = 15 degrees Celsius
t₂ = The final temperature = 80 degrees Celsius
α = temperature coefficient of resistance of tungsten = 0.004/°C
Therefore, we have;
R₂ = 12×[1 + 0.004×(80 - 15)] = 15.12 ohm
The resistance of the tungsten coil at 80 degrees Celsius = 15.12 ohm.
Answer:
D
Explanation:
From the information given:
The angular speed for the block 
Disk radius (r) = 0.2 m
The block Initial velocity is:

Change in the block's angular speed is:

However, on the disk, moment of inertIa is:

The time t = 10s
∴
Frictional torques by the wall on the disk is:

Finally, the frictional force is calculated as:


Velocity is the displacement of an object during a specific unit of time. Explanation: The standard unit of velocity is metre per second.
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