Answer:

Explanation:
Given that,
The distance between two spheres, r = 25 cm = 0.25 m
The capacitance, C = 26 pF = 26×10⁻¹² F
Charge, Q = 12 nC = 12 × 10⁻⁹ C
We need to find the work done in moving the charge. We know that, work done is given by :

Put all the values,

So, the work done is
.
In order to calculate the thermal energy, first let's calculate the power, using the formula:

For a voltage V = 9 Volts and a resistance R = 50 ohms, we have:

Now, multiplying the power by the time (in seconds), we can find the energy:

In scientific notation, we have an energy of 7.3 * 10^2 J, therefore the correct option is the fourth one.
In object in motion stays in motion; speed
Heat required to raise the temperature of a given system is

here we know that
m = mass
s = specific heat capacity
= change in temperature
now as we know that
mass of wood = 5 kg
mass of aluminium pan = 2 kg
change in temperature = 45 - 20 = 25 degree C
specific heat capacity of wood = 1700 J/kg C
specific heat capacity of aluminium = 900 J/kg C
now here we will find the total heat to raise the temperature of both




So heat required to raise the temperature of the system is 257500 J
Answer: A
Explanation: isotopes of the same thing element have the same number of protons in the nucleus but differ in the number of neutrons.