Physics Test 16...

A reversible engine converts one-sixth of the heat input into work. When the temperature of the sink is reduced by  the efficiency of the engine is doubled. The temperatures of the source and sink are

A gas mixture consists of 2 moles of oxygen and 4 moles of Argon at temperature T. Neglecting all vibrational moles, the total internal energy of the system is

A pendulum with time period of 1s is losing energy due to damping. At certain time its energy is 45 J. If after completing 15 oscillations, its energy has become 15 J, its damping constant is:

A sound absorber attenuates the sound level by 20 dB. The intensity decreases by a factor of

A small sphere carrying a charge ‘q’ is hanging in between two parallel plates by a string of length L. Time period of pendulum is T₀. When parallel plates are charged, the time period changes to T. The ratio T/T₀ is equal to

The space between the plates of a parallel plate capacitor is filled with a ‘dielectric’ whose ‘dielectric constant’ varies with distance as per the relation:

The capacitance C, of the capacitor, would be related to its vacuum capacitance C₀ for the relation:

The length of a given cylindrical wire is increased by 100%. Due to the consequent decrease in diameter the change in the resistance of the wire will be

A beam of electrons is moving with constant velocity in a region having simultaneous perpendicular electric and magnetic fields of strength  T respectively at right angles to the direction of motion of the electrons. Then the velocity of electrons must be

A vibration magnetometer consists of two identical bar magnets placed one over the other such that they are perpendicular and bisect each other. The time period of oscillation in a horizontal magnetic field is seconds.

One of the magnets is removed and if the other magnet oscillates in the same field, then the time period in seconds is

The magnitude of the field increases with time.  are the currents in the segments ab and cd. Then,