Physics Test - ...

A radioactive nuclide can decay simultaneously by two different processes, which have individual decay constantsλ₁ anaλ₂ . The effective decay constant of the nuclide (λ) is given by

A point source emits sound equally in all directions in a non-absorbing medium. Two points P and Q are at distances of 2 m and 3 m, respectively, from the source. The ratio of intensities of the waves at P and Q is

Two weights 'w₁' and 'w₂' are suspended by two strings on a frictionless pulley. When the pulley is pulled up with an acceleration 'g', then the tension in the string is-

In photoelectric effect, we assume that photon energy is proportional to its frequency and is completely absorbed by the electrons in metal. Then, the photoelectric current

In an LCR series circuit, the potential difference between the terminals of the inductance is 60 V, that between the terminals of the capacitor is 30 V and that across the resistance is 40 V. Then, the supply voltage will be

A toy of mass M₁ is pulled along a horizontal frictionless surface by rope of mass M₂. A force F is applied to the free end of the rope. the force exerted on the toy is:

The disc of a siren containing 60 holes rotates at a constant speed of 360 rpm. The emitted sound is in unison with a tuning fork of frequency

The displacement y of a particle executing periodical motion is given by y = 4 cos² (t/2) sin (1000t). This expression may be considered to be a result of the superposition of how many independent harmonic motions?

A circular metal plate of radius 'R' is rotating with a uniform angular velocity 'ω' with its plane perpendicular to a uniform magnetic field B. Then, emf developed between the centre and the rim of the plate is

During the adiabatic expansion of 2 moles of a gas, the internal energy was found to have decreased by 100 J. The work done by the gas in this process is