List of practice Questions

A bullet of mass $m$ moving with velocity $v$ strikes a suspended wooden block of mass $M$. If the block rises to a $S$ height the initial velocity of the block will be

A body falls freely from the top of a tower. It covers $36\%$ of the total height in the last second before striking the ground level. The height of the tower is

Rhizophora is a characteristic component of

The term biosystematics was coined by

The fungus commonly known as bread mould is

The fundamental frequency of a closed pipe is $220 \,Hz$. If $\frac{1}{4}$ of the pipe is filled with water, the frequency of the first overtone of the pipe now is

A battery is connected to a uniform resistance wire $AB$ and $B$ is earthed. Which one of the graphs below shows how the current density $J $ varies along $AB$?

A winding wire which is used to frame a solenoid can bear a maximum $10\, A$ current. If length of solenoid is $80\, cm$ and its cross-sectional radius is $3\, cm$ then required length of winding wire is $(B=0.2\, T)$

An inductor $ L,\,\,a $ capacitor of $ 20\mu F $ and a resistor of $ 10\Omega $ are connected in series with an $AC$ source of frequency $ 50\,Hz $ . If the current is in phase with the voltage, then the inductance of the inductor is

A rifle shoots a bullet with a muzzle velocity of $ 500\,m{{s}^{-1}} $ at a small target $ 50\,m $ away. To hit the target the rifle must be aimed (take$ g=10\,m{{s}^{-2}}) $

In an $ AC $ circuit the potential difference V and current i are given respectively by $ V=100\sin (100t) $volt and $ i=100\sin \left( 100t+\frac{\pi }{3} \right)mA $ The power dissipated in the circuit will be

Let $f : R \to R$ be a positive increasing function with $\displaystyle \lim_{x \to \infty} \frac{f\left(3x\right)}{f\left(x\right)} =1$ Then $\displaystyle \lim_{x \to\infty} \frac{f\left(2x\right)}{f\left(x\right)} = $

If the vectors $\vec{a} = \hat{i}- \hat{j}+2 \hat{k}, \vec{b} = 2\hat{i}+4 \hat{j}+ \hat{k}$ and $\vec{c} = \lambda\hat{i}+ \hat{j}+\mu \hat{k}$ are mutually orthogonal, then $\left(\lambda, \mu\right) = $

A particle is moving with velocity $\vec{v} = k\left(y\hat{i} + x\hat{j}\right),$ where $k$ is a constant. The general equation for its path is

A block of mass $10\, kg$ is moving in $x$-direction with a constant speed of $10\, m / s$. It is subjected to a retarding force $F=-0.1 \times J / m$ during its travel from $x=20\, m$ to $x=30\, m$. Its final kinetic energy will be :

A $12\, HP$ motor has to be operated $8\, h /$ day. How much will it cost at the rate of $50$ paise/kWh in 10 days?

When an ideal monoatomic gas is heated at consant pressure, fraction of heat energy supplied which increases the internal energy of gas, is

A body of mass $m$ rises to a height $h=\frac{R}{5}$ from the earth's surface where $R$ is earth's radius. If $g$ is acceleration due to gravity at the earth's surface, the increase in potential energy will be

A force $F$ is applied on the wire of radius $r$ and length $L$ and change in the length of wire is $l$. If the same force $F$ is applied on the wire of the same material and radius $2\, r$ and length $2\, L$, then the change in length of the other wire is

A network of four capacitors of capacities equal to $C_{1}=C, C_{2}=2 C, C_{3}=3 C$ and $C_{4}=4 C$ are connected to a battery as shown in the figure.

The ratio of the charges on $C_{2}$ and $C_{4}$ is

The work functions for metals $A, B$ and $C$ are respectively $1.92\, eV,\, 2.0\, eV$ and $5\, eV$. According to Einstein's equation, the metal(s) which will emit photoelectrons for a radiation of wavelength $4100\,?$ is/are

The ratio of the dimensions of Plancks constant and that of the moment of inertia is the dimensions of

Application of a forward bias to a $p-n$ junction

A $1\, kg$ stone at the end of $1\, m$ long string is whirled in a vertical circle at constant speed of $4\, m / s$. The tension in the string is $6\, N$, when the stone at $\left(g=10\, m / s ^{2}\right)$

The core of any transformer is laminated so as to