List of top Physics Questions

Avalanche breakdown in a $ p $ - $ n $ junction diode is due to

Any digital circuit can be realised by repetitive use of only

An object moving at a speed of $ 5\,m/s $ towards a concave mirror of focal length $ f = 1\, m $ is at a distance of $ 9\, m $ . The average speed of the image is

An $n-p-n$ transistor is biased to work as an amplifier. Which of the following statements is false?

A travelling wave is represented by the equation $y=\frac{1}{10} \sin (60 t+2 x)$, where $x$ and $y$ are in meter and $t$ is in second. This represents a wave 1. travelling with a velocity of $30\, ms ^{-1}$ 2. of frequency $\frac{30}{\pi} Hz$ 3. of wavelength $\pi$ meter 4. of amplitude $10\, cm$ 5. moving in the positive $x$-direction Pick out the correct statements from the above.

A thin uniform annular disc (see figure) of mass $M$ has outer radius $4R$ and inner radius $3R$. The work required to take a unit mass from point $P$ on its axis to infinity is

A student uses a simple pendulum of exactly $1 \,m$ length to determine $g$, the acceleration due to gravity. He uses a stopwatch with the least count of $1$ second for this and records $40$ seconds for $20$ oscillations. For this observation, which of the following statements is true ?

A square loop of wire, side length $ 10\,cm $ is placed at angle of $ 45^{\circ} $ with a magnetic field that changes uniformly from $ 0.1 \,T $ to zero in $ 0.7\, s $ . The induced current in the loopa (its resistance is $ 1\,\Omega $ ) is

A square card of side length $ 1 \,mm $ is being seen through a magnifying lens of focal length $ 10 \,cm $ . The card is placed at a distance of $ 9 \,cm $ from the lens. The apparent area of the card through the lens is

A pure inductor of $25 \,mH$ is connected to a source of $220\, V$. Given the frequency of the source as $50\, Hz$, the $rms$ current in the circuit is

A pure inductive coil of $ 30\,mH $ is connected to an $ AC $ source of $ 220 \,V $ , $ 50 \,Hz $ . The $ rms $ current in the coil is

A point mass of 1 kg collides elastically with a stationary point mass of 5 kg. After their collision, the 1 kg mass reverses its direction and moves with a speed of 2 ms ~ . Which of the following statement(s) is/are correct for the system of these two masses?

Which one of the following is not associated with the total internal reflection?

The following figure represents

A block of mass $m$ is placed on a smooth sphere of radius $R$. It slides when pushed slightly. At what distance $h$, from the top, will it leave the sphere?

Choose the incorrect statement out of the following.

If $E, M, L$ and $G$ denote energy, mass, angular momentum and gravitational constant respectively, then the quantity $\left(E^{2} L^{2} / M^{5} G^{2}\right)$ has the dimensions of

A body $A$ is thrown up vertically from the ground with a velocity $v_{0}$ and another body $B$ is simultaneously dropped from a height $H$. They meet at a height $\frac{H}{2}$ if $v_{0}$ is equal to

An AC voltage source of variable angular frequency to and fixed amplitude $V_0$ is connected in series with a capacitance $C$ and an electric bulb of resistance $R$ (inductance zero). When to is increased

A ray $OP$ of monochromatic light is incident on the face $AB$ of prism $ABCD$ near vertex $B$ at an incident angle of $60^{\circ}$ (see figure). If the refractive index of the material of the prism is $\sqrt3$, which of the following is (are) correct?

One mole of an ideal gas in initial state A undergoes a cyclic process ABC A, as shown in the figure. Its pressure at A is p$_0$. Choose the correct option(s) from the following.

A biconvex lens of focal length $15\, cm$ is in front of a plane mirror. The distance between the lens and the mirror is $10\,cm$. A small object is kept at a distance of $30\,cm$ from the lens. The final image is

$A$ block of mass $m$ is on an inclined plane of angle $\theta$. The coefficient of friction between the block and the plane is $\mu$ and tan $\theta >\mu.$ The block is held stationary by applying a force $P$ parallel to the plane. The direction of force pointing up the plane is taken to be positive. As $P$ is varied from $P_{1}=mg$ $\left(sin\,\theta-\mu\,cos\,\theta\right)$ to $P_{2}=mg$ $\left(sin\theta+\mu cos\theta\right)$, the frictional force $f$ versus $P$ graph will look like

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

The longest and the shortest distance of our planet from sun is and $R_1$ and $R_2$. Distance from sun when it is normal to major axis of orbit is .