COMEDK · Physics · 6. Work Power Energy
A wind mill converts a fixed fraction of the wind energy intercepted by its blades into electrical energy. The electrical power output P is related to the velocity of wind v as
- A \(v^3\)
- B \(v^2\)
- C \(v^{3 / 2}\)
- D \(\mathrm{v}^{5 / 2}\)
Answer & Solution
Correct Answer
(A) \(v^3\)
Step-by-step Solution
Detailed explanation
The kinetic energy \(K\) of a mass \(m\) of air moving with velocity \(v\) is given by \(K = \dfrac{1}{2}mv^2\). The mass \(m\) of air passing through an area \(A\) in time \(t\) is \(m = \rho A v t\), where \(\rho\) is the density of air. The power \(P\) is the rate of change…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- The charges \(Q,+q\) and \(+q\) are placed at the vertices of an equilateral triangle of side \(l\). If the net electrostatic potential energy of the system is zero, then \(Q\) is equal toCOMEDK 2018 Easy
- The loudness and pitch of a sound note depends onCOMEDK 2019 Medium
- Which of the following laws of Physics is valid across all domains of nature?COMEDK 2020 Easy
- In the given circuit, if the barrier potential across the diode is 0.5 V , the current in the circuit is:
COMEDK 2025 Medium - The normal magnetic flux passing through a coil changes with time according to the equation \(\phi=6 t^{2}-5 t+1\). What is the magnitude of the induced current at \(t=0.253 \mathrm{~s}\) and resistance \(10 \Omega\) ?COMEDK 2014 Medium
- A moving coil galvanometer has 28 turns and area of coil is \(4 \times 10^{-2} \mathrm{~m}^{2}\). If the magnetic field is \(0.2 \mathrm{~T}\), then to increase the sensitivity by \(25 \%\) without changing area and field, the number of turns should be changed toCOMEDK 2020 Easy
More PYQs from COMEDK
- \(\text { The function } f(x)=\tan ^{-1}(\sin x+\cos x) \text { is an increasing function in }\)COMEDK 2024 Medium
- A sonometer string vibrates with a frequency of 400 Hz . When the length of the string is halved and the tension is altered, it begins to vibrate with a frequency of 200 Hz . The ratio of the new tension to the original tension in the string is:COMEDK 2025 Medium
- An unknown resistance \(R_{1}\) is connected in series with a resistance of \(10 ~\Omega\). This combination is connected to one gap of a meter bridge, while a resistance \(R_{2}\) is connected in the other gap. The balance point is at \(50 \mathrm{~cm}\). Now, when the \(10 ~\Omega\) resistance is removed, the balance point shifts to \(40 \mathrm{~cm}\). The value of \(R_{1}\) (in \(\Omega\) ) isCOMEDK 2013 Medium
- The electric field versus distance graph is shown as given. Select the correct statement from the following.
E- electric field
R-radius
r - distance from the centre
COMEDK 2025 Medium - If a straight line passing through a fixed point \((a, b)\), where \(a, b > 0\), makes positive intercepts OA and OB on the coordinate axes, then the least value of OA + OB is:COMEDK 2026 Medium
- In a nuclear fusion reaction, two nuclei, \(A\) and \(B\) fuse to produce a nucleus \(C\), releasing an amount of energy \(\Delta \mathrm{E}\) in the process. If the mass defects of the three nuclei are \(\Delta M_A, \Delta M_B\) and \(\Delta M_C\) respectively, then which of the following relations is true? ( \(c\) is the speed of light).COMEDK 2025 Medium