A ball is thrown from ground at an angle $$\theta $$ with horizontal and with an initial speed u0. For the resulting projectile motion, the magnitude of average velocity of the ball up to the point when it hits the ground for the first time is V1. After hitting the ground, the ball rebounds at the same angle $$\theta $$ but with a reduced speed of $${{{u_0}} \over \alpha }$$. Its motion continues for a long time as shown in figure. If the magnitude of average velocity of the ball for entire duration of motion is 0.8 V1, the value of $$\alpha $$ is ..................
Your input ____
2
JEE Advanced 2019 Paper 2 Offline
Numerical
+3
-0
A 10 cm long perfectly conducting wire PQ is moving with a velocity I cm/s on a pair of horizontal rails of zero resistance. One side of the rails is connected to an inductor L = 1 mH and a resistance R = 1$$\Omega $$ as shown in figure. The horizontal rails, L and R lie in the same plane with a uniform magnetic field B = 1 T perpendicular to the plane. If the key S is closed at certain instant, the current in the circuit after 1 millisecond is x $$ \times $$ 10-3 A, where the value of x is ...........
[Assume the velocity of wire PQ remains constant (1 cm/s) after key S is closed. Given e-1 = 0.37, where e is base of the natural logarithm]
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3
JEE Advanced 2019 Paper 2 Offline
MCQ (Single Correct Answer)
+3
-1
A musical instrument is made using four different metal strings, 1, 2, 3 and 4 with mass per unit length $$\mu $$, 2$$\mu $$, 3$$\mu $$ and 4$$\mu $$ respectively. The instrument is played by vibrating the strings by varying the free length in between the range L0 and 2L0. It is found that in string-1$$\mu $$ at free length L0 and tension T0 the fundamental mode frequency is f0.
List-I gives the above four strings while list-II lists the magnitude of some quantity.
If the tension in each string is T0, the correct match for the highest fundamental frequency in f0 units will be
A
I $$ \to $$ P, II $$ \to $$ Q, III $$ \to $$ T, IV $$ \to $$ S
B
I $$ \to $$ P, II $$ \to $$ R, III $$ \to $$ S, IV $$ \to $$ Q
C
I $$ \to $$ Q, II $$ \to $$ S, III $$ \to $$ R, IV $$ \to $$ P
D
I $$ \to $$ Q, II $$ \to $$ P, III $$ \to $$ R, IV $$ \to $$ T
4
JEE Advanced 2019 Paper 2 Offline
MCQ (Single Correct Answer)
+3
-1
A musical instrument is made using four different metal strings, 1, 2, 3 and 4 with mass per unit length $$\mu $$, 2$$\mu $$, 3$$\mu $$ and 4$$\mu $$ respectively. The instrument is played by vibrating the strings by varying the free length in between the range L0 and 2L0. It is found that in string-1$$\mu $$ at free length L0 and tension T0 the fundamental mode frequency is f0.
List-I gives the above four strings while list-II lists the magnitude of some quantity.
The length of the strings 1, 2, 3 and 4 are kept fixed at L0, $${{3{L_0}} \over 2}$$, $${{5{L_0}} \over 4}$$ and $${{7{L_0}} \over 4}$$ respectively. Strings 1, 2, 3 and 4 are vibrated at their 1st, 3rd, 5th and 14th harmonies, respectively such that all the strings have same frequency.
The correct match for the tension in the four strings in the units of T0 will be
A
I $$ \to $$ P, II $$ \to $$ R, III $$ \to $$ T, IV $$ \to $$ U
B
I $$ \to $$ P, II $$ \to $$ Q, III $$ \to $$ R, IV $$ \to $$ T
C
I $$ \to $$ P, II $$ \to $$ Q, III $$ \to $$ T, IV $$ \to $$ U
D
I $$ \to $$ T, II $$ \to $$ Q, III $$ \to $$ R, IV $$ \to $$ U
