List of practice Questions

A solid sphere falls with a terminal velocity of $20\, m/s$ in air. If it is allowed to fall in vacuum?
A shell fired from a gun at sea level rises to a maximum height of $ 5\, km $ when fired at a ship $ 20 \,km $ away. The muzzle velocity should be
A conductor (shown in the figure) carrying constant current $I$ is kept in the $x-y$ plane in a uniform magnetic field $\vec{B}$. If $F$ is the magnitude of the total magnetic force acting on the conductor, then the correct statement(s) is(are)
A rectangular loop of sides $10\, cm$ and $5\, cm$ carrying a current $I$ of $12 \,A$ is placed in different orientations as shown in the figures below,
If there is a uniform magnetic field of $0.3\, T$ in the positive $z$-direction in which orientations the loop would be in (i) stable equilibrium and (ii) unstable equilibrium?
A quarter horse power motor runs at a speed of $ 600\, rpm $ . Assuming $ 40\% $ efficiency, the work done by the motor in the one rotation will be
A long wire carrying a steady current is bent into a circular loop of one turn. The magnetic field at the centre of the loop is $B$. It is then bent into a circular coil of $n$ turns. The magnetic field at the centre of this coil of $n$ turns will be
The electronegativity of elements helps in predicting
Consider the family of all circles whose centers lie on the straight line $y = x$. If this family of circles is represented by the differential equation $Py" + Qy' + 1 = 0$, where $P$, $Q$ are functions of $x, y$ and $y'$ (here $y' = \frac{dy}{dx}, \,y'' = \frac{d^{2}y}{dx^{2}}$), then which of the following statements is (are) true ?
Verhulst-PearP is associated with the equation
A decline in population size will be in the stimulation
The distribution of species diversity on earth may be best described as
The correct statement is
The adaptation in an organism is meant for
A example of CAM plant is
A circular loop of area $1\,cm^{2} $ , carrying a current of $10\,A$ is placed in a magnetic field of $0.1\,T$ perpendicular to the plane of the loop. The torque on the loop due to the magnetic field is
According to Newton's law of cooling, the rate of cooling of a body is proportional to $(\Delta \theta)^n$, where $\Delta \theta$ is the difference of the temperature of the body and the surroundings, and $n$ is equal to
If $ S $ is the stress and $ Y $ is the Young?s modulus of material of a wire, the energy stored in the wire per unit volume is
From a building two balls $A$ and $B$ are thrown such that $A$ is thrown upwards and $B$ downwards with the same speed (both vertically). If $v_A$ and $v_B$ are their respective velocities on reaching the ground then,
In a transformer the number of primary turns is four times that of the secondary turns. Its primary is connected to an $AC$ source of voltage $V$. Then,
Which of the following is NOT an electromagnetic wave?
A parallel narrow-beam of light is falling normally on a glass sphere. It will come to a focus
The shortest distance between the lines $ \frac{x}{-1}=\frac{y}{1}=\frac{z}{1} $ and $ \frac{x-3}{0}=\frac{y+3}{1}=\frac{z-3}{-1} $ is
A fair die is rolled. Consider the events A = { $ 1, 3, 5 $ }, B = { $ 2, 3 $ } and C = { $ 2, 3, 4, 5 $ }. Then, the conditional probability $ P (A \cup B / C) $ is
$20\, dm^{3}$ of $SO_{2}$ diffuse through a porous partition in $60\, s$. What volume of $O_{3}$ will diffuse under similar conditions?
Which one of the following is planar?