Answer:

Explanation:
Given that:
Absolute temperature of the body, 
- emissivity of the body,

<u>Using Stefan Boltzmann Law of thermal radiation:</u>

where:
(Stefan Boltzmann constant)
Now putting the respective values:


Explanation:
Formula to calculate electric field because of the plate is as follows.
E =
=
=
Now, we will consider that equilibrium of forces are present there. So,
ma = qE
a =
=
According to the third equation of motion,
or, d = 
= 
= 0.254 m
Thus, we can conclude that
the proton will travel 0.254 m before reaching its turning point.
Answer:
B) Friction
Explanation:
The main source of error is the omission of the effect from friction between block and incline, which is directly proportional to the mass of the block. The force of gravity is constant. The friction force dissipates part of the gravitational potential energy, generating a final speed less than calculated under the consideration of a conservative system. Air resistance is neglected at low speeds like this case.
Answer : The correct option is, (d) 
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.


where,
= specific heat of copper = 
= specific heat of water = 
= mass of copper = 120 g
= mass of water = 300 g
= final temperature of mixture = 
= initial temperature of copper = ?
= initial temperature of water =
Now put all the given values in the above formula, we get:


Therefore, the temperature of the kiln was, 
Answer:
If R₂=25.78 ohm, then R₁=10.58 ohm
If R₂=10.57 then R₁=25.79 ohm
Explanation:
R₁ = Resistance of first resistor
R₂ = Resistance of second resistor
V = Voltage of battery = 12 V
I = Current = 0.33 A (series)
I = Current = 1.6 A (parallel)
In series

In parallel


Solving the above quadratic equation


∴ If R₂=25.78 ohm, then R₁=10.58 ohm
If R₂=10.57 then R₁=25.79 ohm