List of practice Questions

The half-life of a radioactive substance is:
The S.I. unit of decay constant is:
Number of neutrons in an atom of \(^{230}_{90}\mathrm{Th}\) is:
P-N junction diode is used as:
Instrument used to increase input voltage/current is called:
If in a logic gate output \(Y\) is obtained by the product of its both inputs \(A \cdot B\), then the gate is:
Width of forbidden energy gap in the semiconductor is approximately:
Convex lens is used in:
The colour of the sky is blue due to:
The fringe width in interference of light due to two coherent sources is:
Two sources of monochromatic light are coherent when their:
The de Broglie wavelength is:
Photocell is based on:
Cathode rays are group of:
A large virtual image of an object is formed by:
Powers of two lenses kept in contact are \( P_1 \) and \( P_2 \). The power of the equivalent lens will be:
The wavelength of which colour is minimum?
Which causes the formation of rainbow?
The image formed in a compound microscope is:
The image of any object formed at the retina of the human eye is:
What value of alternating current is measured by a hot wire ammeter?
If magnetic field \( B \) is perpendicular to surface area vector \( \mathbf{ds} \), then the magnetic flux on area \( ds \) will be:
Mean value of alternating current in a full cycle is:
If the phase difference between alternating current and e.m.f is \(\phi\), then the value of power factor is:
In an AC circuit, power is lost in only: