NDA Physics Questions

A particle is moved from point X to point Y under a force field. The work done depends only on the initial and final speeds. Which one of the following is correct?

An object is placed far beyond the centre of curvature of a concave mirror. The object then starts accelerating towards the mirror. Which one of the following is correct?

The position vector of a particle is given by $\vec{r}=\sqrt{3}{t}^2\hat{i}+\sqrt{2}t\hat{j}+\sqrt{5}\hat{k}$. Which one of the following statements is correct?

A constant power machine pulls a block on a smooth horizontal surface. Which one of the following correctly describes the relation between speed of the block ($v$) and time ($t$)?

A floating body is in stable state. Which one of the following is correct?

A periscope uses two plane mirrors inclined at $45^{\circ }$. If the tube of the periscope is filled with a complete transparent liquid of refractive index $1.5$, then which one of the following is correct in respect of the image seen?

Two forces of equal magnitude simultaneously act at a point. It is observed that the resultant force is equal in magnitude to the individual forces. Which of the following statements is/are correct?

I. The angle between one of the individual forces and the resultant force is $\pi /3$.

II. The angle between the individual forces is $2\pi /3$.

Select the answer using the code given below.

A glass slab of refractive index $1.5$ is cut in the shape of a parallelepiped $ABCD$ as shown in the figure. Surface $BC$ is polished to form a perfect reflector. Light is incident at surface $AB$ from inside at an angle $\pi /3$. Which one of the following is the correct angle $ABC$ ($\theta$) such that the reflected light retraces its path?

For an object in gravitational field, the gravitational potential is the same at two points A and B, but the gravitational field is not the same at these two points. Which one of the following statements is correct?

A pendulum of length $L$ oscillates with an angular amplitude of $\theta =60^{\circ }$ and time period $T$. Let $T_0=2\pi \sqrt{\frac{L}{g}}$ be the time period for small angle of oscillations, where $g$ is the acceleration due to gravity. If air resistance is negligibly small and the string remains straight, then which one of the following is correct?

A ball is dropped from rest from height $h$ above the ground in frame S (the Earth's frame). Another frame S' is moving upwards with constant speed $u$ relative to the Earth. In frame S', the ball has initial downward speed $u$. Pertaining to the change in kinetic energy ($\Delta K$) of the ball from release to just before hitting the ground as measured in frames S and S' separately, which one of the following is correct?

A solid of mass $m$ has temperature-dependent specific heat as $C(T)=C_0+\alpha T$, where $C_0$ and $\alpha$ are constants. The solid is heated from $T_1$ to $T_2$. Which one of the following is the correct expression for quantity of heat $Q$ of the solid mass?

A light ray is falling on a face of an equilateral glass prism as shown in the figure. (A small inset shows the prism with apex angle $60^{\circ }$ and the internal ray making $90^{\circ }$ with the base.) Which one of the following diagrams correctly shows the complete path of the ray through the glass prism?

Consider the following statements in case of terrestrial planets :
I. Mercury, Venus, Earth and Mars are terrestrial planets having low densities as compared to other planets.
II. They lie between the Sun and the belt of asteroids.
III. Their lower gravity can hold the escaping gases.
Which of the statements given above is/are correct?

It has been observed that a mirror always forms the image between the pole and the focus, irrespective of the location of the object. Which one of the following is correct in respect of the nature of the mirror?

One year at a planet is 8 times as large as compared to the one year at the Earth. Which one of the following is correct about the planet's orbit?

Three wires each of length $L$, cross-sectional area $A$ and resistivity $\rho$ are connected as shown in the figure: two identical wires form a loop between points X and Y (top and bottom) and a third identical wire connects Y to Z. These are to be replaced by another wire of same resistivity such that the resistance between points X and Z does not change. If $L_1$ is the length and $A_1$ is the cross-sectional area of the new wire, then which one among the following is correct?

A lightning rod with sharp tip reduces damage risk. Which one of the following is the primary reason for it?

A person jumps from a height on soft sand. Which one of the following is the correct reason for less likely injury to the person?

In a certain process, the relation between pressure ($P$) and volume ($V$), for an ideal gas, is given by $P{V}^2=$ constant. If the initial temperature is $T_1$ and the final temperature is $T_2$; and the initial volume is $V_1$ and the final volume is $V_2$, then which one of the following is correct?