Neet 2005 PYQ Free Mock Test

For skywave propagation of a $10\text{MHz}$ signal, what should be the minimum electron density in the ionosphere?

Which of the following logic gates is an universal gate?

What should be the maximum acceptance angle at the air-core interface of an optical fibre if $n_1$ and $n_2$ are the refractive indices of the core and the cladding, respectively?

A conducting ring of radius $1\text{meter}$ is placed in a uniform magnetic field $B$ of $0.01\text{tesla}$ oscillating with frequency $100\text{Hz}$ with its plane at right angles to $B$. What will be the induced electric field?

Consider an $n$ -$p$ -$n$ transistor amplifier in common-emitter configuration. The current gain of the transistor is $100$. If the collector current changes by $1\text{mA}$, what will be the change in emitter current?