700 J is the work done by the system.
<u>Explanation:</u>
The first law of thermodynamics is that the change in internal energy of the system is equal to the net heat transfer to the system minus the complete work performed by the system.

Where,
∆U – Change in internal energy
Q – Heat transfer to the system
Q – Work done
Here,
<u>Given data:</u>
∆U - 400 J
Q - 1100 J
We need to the work done by the system (W)
By applying the given values in the above equation, we get
400 = 1100 - W
W = 1100 - 400 = 700 J
Question 8
Silicon is a semi-conductor that are mostly used in electronic devices. From the choices give, silicon is applicable in t<span>ransistor, integrated circuit and diode. But the best answer that suits this question is (B) integrated circuit.
Question 9
Power is the rate of doing work. It is calculated as,
Power = workdone/time taken to do that work.
In electricity, power = current </span>×voltage
From ohm's law, V=IR
Where I⇒current and
R⇒ resistance.
∴Power = I²R
= 6²×5
= 180 Watts
Answer:
38 cm from q1(right)
Explanation:
Given, q1 = 3q2 , r = 60cm = 0.6 m
Let that point be situated at a distance of 'x' m from q1.
Electric field must be same from both sides to be in equilibrium(where EF is 0).
=> k q1/x² = k q2/(0.6 - x)²
=> q1(0.6 - x)² = q2(x)²
=> 3q2(0.6 - x)² = q2(x)²
=> 3(0.6 - x)² = x²
=> √3(0.6 - x) = ± x
=> 0.6√3 = x(1 + √3)
=> 1.03/2.73 = x
≈ 0.38 m = 38 cm = x
Speed is scalar, meaning it's only going to be like 74 mph, doesn't matter which direction. Velocity is a vector, meaning it has direction. You can go -74mph when talking about velocity, not speed.