List of practice Questions

The working of a rocket is based on the principle of:
A radioactive substance has a half-life of 60 min. During 3 hours, the fraction of the substance that has decayed is:
In a Young's double slit experiment, if the distance between the slits is halved and the distance of the screen from the slits is doubled, then the fringe width will:
A door 1.6 m wide requires a force of 1 N to be applied at the free end to open or close it. The force that is required at a point 0.4 m distance from the hinges for opening or closing the door is
The electric potential at a point on the axial line of an electric dipole is:
The unit of Planck's constant is:
A step-up transformer operates on a 230 V line and supplies a load of 2 A. The ratio of primary to secondary windings is 1:25. The current in the primary is:
The resistance of an ideal ammeter is:
The process by which a heavy nucleus splits into two lighter nuclei is called:
In an L-C-R series circuit, at resonance, the phase difference between current and voltage is:
Light of wavelength 5000 falls on a sensitive plate with photoelectric work function 1.9 eV. The kinetic energy of the photoelectron is:
The amount of energy released when one microgram of matter is annihilated is
The number of significant figures in the numbers $4.8000 \times 10^4$ and 48000.50 are respectively
$\beta$-decay means emission of electron from
An electric heater rated 220 V and 550 W is connected to AC mains. The current drawn by it is
According to Newton's corpuscular theory, the speed of light is
For the constructive interference the path difference between the two interfering waves must be equal to
The accurate measurement of emf can be obtained using
The kinetic energy of an electron gets tripled, then the de-Broglie wavelength associated with it changes by a factor
Which of the following is not a thermodynamic coordinate?
Two solid pieces, one of steel and the other of aluminium when immersed completely in water have equal weights. When the solid pieces are weighed in air
Three resistors 1 $\Omega$, 2 $\Omega$ and 3 $\Omega$ are connected to form a triangle. Across 3 $\Omega$ resistor a 3 V battery is connected. The current through 3 $\Omega$ resistor is
In a common emitter amplifier the input signal is applied across
In a radioactive disintegration, the ratio of initial number of atoms to the number of atoms present at an instant of time equal to its mean life is
Ferromagnetic materials used in a transformer must have