The angle of elevation of a cloud $C$ from a point $P , 200 m$ above a still lake is $30^{\circ} .$ If the angle of depression of the image of $C$ in the lake from the point $P$ is $60^{\circ}$, then $P C$ (in $m$ ) is equal to :
- 400
- $400 \sqrt{3}$
- 100
- $200 \sqrt{3}$
The Correct Option is A
Solution and Explanation
Top JEE Main Mathematics Questions
- The value of is
- The number of terms of an is even. The sum of the odd terms is and of the even terms is . The last term exceeds the first by . Then the number of terms in the series is ______.
- If , then the general value of is:
- The general solution of
- If the constant term in the binomial expansion of $\left(\frac{x^{\frac{3}{2}}}{2}-\frac{4}{x^l}\right)^9$ is $-84$ and the coefficient of $x^{-3 l}$ is $2^\alpha \beta$, where $\beta<0$ is an odd number, then $|\alpha l-\beta|$ is equal to_____
Top JEE Main Questions
- Two masses $m$ and $\frac{m}{2}$ are connected at the two ends of a massless rigid rod of length $l$. The rod is suspended by a thin wire of torsional constant $k$ at the centre of mass of the rod-mass system(see figure). Because of torsional constant $k$, the restoring torque is $\tau =k\theta$ for angular displacement $\theta$. If the rod is rota ted by $\theta_0$ and released, the tension in it when it passes through its mean position will be:
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)- The value of is
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A black body is at a temperature of 2880 K. The energy of radiation emitted by this body with wavelength between 499 nm and 500 nm is U1, between 999 nm and 1000 nm is U2 and between 1499 nm and 1500 nm is U3. The Wien's constant, b = 2.88×106 nm-K. Then,
Concepts Used:
Measurement of Angles
How to Measure an Angle?
- Measurement Of Angle–Degree Measure
A degree is defined as a complete rotation in either a clockwise direction or anticlockwise direction, where the starting and the ending point are the same. The rotation is dissected into 360 units.
- Measurement Of Angle–Radian Measure
Let's consider a circle of radius one unit. Also, the arc of the circle is one unit. The measure of the angle is 1 radian if the arc subtends at the center of the circle, given the radius and arc lengths are equal. The arc length of a circle with radius unity is equivalent to the angle in radian.
- Measurement Of Angle–Grade Measure
A grade can be described as a right angle split into a hundred (100) equal parts. Further, each grade is dissected into a hundred minutes and each minute into a hundred seconds.