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Three metal blocks A , B and C of masses 10 kg , 20 kg and 30 kg rest on a frictionless table in a line . A is converted to B and B to C by two pieces of string . With the help of a third string attached to C , the system [...]

A whistle revolves in a circle with angular speed ω=20 rad/sec using a string of length 50 cm. If the frequency of sound from the whistle is 385 Hz, then what is the minimum frequency heard by an observer which is far away from the centre : – ( V sound​=340 m/s) A whistle revolves [...]

A thin biconvex lens of refractive index 3/2 is placed on a horizontal plane mirror as shown. The space between the lens and the mirror is then filled with water of refractive index 4/3. It is found that when a point object is placed 15cm above the lens on its principal axis, the object coincides [...]

The metal blocks A and B of masses 2 kg and 1 kg , respectively are in contact on a frictionless table A constant horizontal force of 3 N is applied to the block A . Calculate the force of constant between the two blocks . If the same force is applied to the block [...]

An observer moves towards a stationary source of sound with a speed 1/5 th of the speed of sound. The wavelength and frequency of the source emitted are λ and f, respectively. The apparent frequency and wavelength recorded by the observer are, respectively. An observer moves towards a stationary source of sound with a speed [...]

A car is moving towards a high cliff. The car driver sounds a horn of frequency f. The reflected sound heard by the driver has the frequency 2f. If v be the velocity of sound, then the velocity of the car, in the same velocity units will be : A car is moving towards a [...]

A constant force acts on a body of mass 10 g moving with a velocity of 500ms−1 . The body is found to move with same velocity but in the opposite direction after 10 s . Calculate the magnitude of the force . In the arrangement shown in figure the bodies have masses m0 m1 [...]

a thin rod of length f/3 is placed along the principal axis of a concave mirror of focal length f such that its image which is a real and elongated just touches one of its end of the rod what is its magnification An object is placed at a distance of 20cm from a equi-concave [...]

An object is placed at a distance of 20cm from a equi-concave lens of focal length 30cm, whose one surface is silvered. If the radius of curvature of the silvered surface is 60cm, find the position and nature of the image. An object is placed at a distance of 20cm from a equi-concave lens of [...]

An a.c. source of angular frequency omega is fed across a resistor R and a capacitor C in series. The current registered is I. If you the frequency of source is changed to omega//3, maintaining the same voltage, current in the circuits is found to be halved. Caculate the ratio of reactance to resistance at [...]