A long conducting wire having a current I flowing through it, is bent into a circular coil of $N$ turns .Then it is bent into a circular coil of $n$ turns. The magnetic field is calculated at the centre of coils in both the cases. The ratio of the magnetic field in first case to that of second case is :
A series LCR circuit is connected to a 45 sin (ωt) volt source. The resonant angular frequency of the circuit is 105 rad/sec and the current amplitude at resonance is I0. When the angular frequency of the source is ω = 8 x 104 rad/sec, the current amplitude in the circuit is 0.05 I0. If m = 50 mH, match each entry in the list - I with an approximate value from list - II and choose the option.
The Wheatstone bridge shown in the diagram is balanced. If P3 is the power dissipated by R3 and P1 is the power dissipated by R1, then the ratio P3/P1 is:
For the following logic circuit, the truth table is:
Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R. Assertion (A): Range of a horizontal projectile is maximum when angle of projection is \(θ = 45°\).Reason (R): Range is maximum when \(sin\ (2θ)=1\).In the light of the above statements, choose the correct answer from the options given below
A body is moving with constant speed, in a circle of radius $10 m$ .The body completes one revolution in 4 s .At the end of 3 rd second, the displacement of body (in mi) from its starting point is :
A person of height 1.6 m is walking away from a lamp post of height 4 m along a straight path on the flat ground. The lamp post and the person are always perpendicular to the ground. If the speed of the person is 60 cm s−1, the speed of the tip of the person’s shadow on the ground with respect to the person is _______ cm s−1.
In an experiment for determination of the focal length of a thin convex lens, the distance of the object from the lens is 10 ± 0.1 cm and the distance of its real image from the lens is 20 ± 0.2 cm. The error in the determination of focal length of the lens is 𝑛 %. The value of 𝑛 is ____ .
Match List I with List II
The velocity of a particle having a magnitude of 10 ms-1 in the direction of 60° with positive X-axis is
Expression for an electric field is given by $\overrightarrow{ E }=4000 x^2 i \frac{ V }{ m }$ The electric flux through the cube of side $20 cm$ when placed in electric field (as shown in the figure) is ___$V cm$
A ball falls freely from a height h on a rigid horizontal plane. If the coefficient of resolution is e, then the total distance travelled by the ball before hitting the plane second time is:
