List of top Physics Questions

(a) Which force produces negative moment?
(b) Is the wheel in equilibrium? (Yes or No)
(c) Justify your answer stated in (b).

To lift a load of 30 kgf, Suhas uses a single fixed pulley, while Radha uses a single movable pulley. The displacement of efforts in both the cases are equal. In an ideal situation calculate the ratio of:
(a) the efforts in the two cases.
(b) the potential energy gained by the loads in the two cases.
(c) the efficiencies in the two cases.

A biconvex lens is formed by using two plano-convex lenses as shown in the figure. The refractive index and radius of curvature of surfaces are also mentioned. When an object is placed on the left side of the lens at a distance of $30\,\text{cm}$, the magnification of the image will be:

An atom $ ^8_3X $ is bombarded by a shower of fundamental particles and in 10 s this atom absorbed 10 electrons, 10 protons and 9 neutrons. The percentage growth in the surface area of the nucleus is recorded by:

A thin prism with angle 5° of refractive index 1.72 is combined with another prism of refractive index 1.9 to produce dispersion without deviation. The angle of second prism is :

The reverse side of a three-pin plug with incorrect connection of wires is shown in the diagram below.
(a) Identify the fault in the above connection.
(b) Mention a risk factor involved, if the user operates the appliance with correcting it.
(c) Will the appliance function in the present situation? (Yes or No)

State two factors on which the position of the Center of Gravity of a body depends.

Case 1: Lata cuts a potato into two halves, using a cutter which belongs to a Class II lever. She needed effort E$_1$.
Case 2: Then she cuts one half of this potato again, but this time she needed effort E$_2$.
If E$_1$ > E$_2$ then:
(a) In which case (1st or 2nd) was the potato closer to her hand applying the effort? (Assume normal reaction of the surface of the potato is same in both cases)
(b) Give a reason for your answer in (a) above.

The heat generated in 1 minute between points A and B in the given circuit, when a battery of 9 V with internal resistance of 1 $\Omega$ is connected across these points is ______ J.

Initially a satellite of 100 kg is in a circular orbit of radius 1.5$R_E$. This satellite can be moved to a circular orbit of radius 3$R_E$ by supplying $a \times 10^6$ J of energy. The value of a is_________ . (Take Radius of Earth $R_E = 6 \times 10^6$ m and g = 10 m/s$^2$).

Complete the following: A car is moving in uniform circular motion. The direction of friction between the tyres and the path is _____________.

Equal volumes of water are added to three cylindrical jars A, B and C of the same height and radii $r_A$, $r_B$ and $r_C$ respectively with $r_A<r_B<r_C$. If you blow across the mouth of these jars, which tube will produce the shrillest note?

In the given situation, the force acting at the center on a $1\,\text{kg}$ mass is $F_1$. Now, if the masses $4m$ and $3m$ are interchanged, the force becomes $F_2$. Given that \[ \frac{F_1}{F_2}=\frac{2}{\sqrt{\alpha}}, \] find the value of $\alpha$.

Three small identical bubbles of water having same charge on each coalesce to form a bigger bubble. Then the ratio of the potentials on one initial bubble and that on the resultant bigger bubble is:

Consider a modified Bernoulli equation. \[ P + \frac{A}{Bt^2} + \rho g(h + Bt) + \frac{1}{2} \rho v^2 = \text{constant} \] If t has the dimension of time then the dimensions of A and B are_________ respectively.

Consider two identical metallic spheres of radius $R$ each having charge $Q$ and mass $m$. Their centers have an initial separation of $4R$. Both the spheres are given an initial speed of $u$ towards each other. The minimum value of $u$, so that they can just touch each other is :
(Take $k = \frac{1}{4 \pi \epsilon_0}$ and assume $kQ^2>Gm^2$ where $G$ is the Gravitational constant)

Given below are two statements: Statement I: A satellite is moving around earth in an orbit very close to the earth surface. The time period of revolution of satellite depends upon the density of earth.
Statement II: The time period of revolution of the satellite is \[ T = 2\pi \sqrt{\frac{R_e}{g}} \] (for satellite very close to the earth surface), where $R_e$ is the radius of earth and $g$ is acceleration due to gravity.
In the light of the above statements, choose the correct answer from the options given below.

When a blackened bulb thermometer is moved beyond the red region of the visible spectrum, there is a rapid rise in the temperature. This is due to the presence of:

The energy transformation taking place during photosynthesis in plants is:

What are the charges stored in the $ 1\,\mu\text{F} $ and $ 2\,\mu\text{F} $ capacitors in the circuit once current becomes steady?

Inductance of a coil with $10^4$ turns is $10\,\text{mH}$ and it is connected to a DC source of $10\,\text{V}$ with internal resistance $10\,\Omega$. The energy density in the inductor when the current reaches $ \left(\frac{1}{e}\right) $ of its maximum value is \[ \alpha \pi \times \frac{1}{e^2}\ \text{J m}^{-3}. \] The value of $ \alpha $ is _________.
\[ (\mu_0 = 4\pi \times 10^{-7}\ \text{TmA}^{-1}) \]

In a microscope of tube length $10\,\text{cm}$ two convex lenses are arranged with focal lengths $2\,\text{cm}$ and $5\,\text{cm}$. Total magnification obtained with this system for normal adjustment is $(5)^k$. The value of $k$ is ___.

(a) Name the electromagnetic radiation used to detect fake currency.
(b) Redraw the diagram given below and complete the path of the light ray AB through the glass prism till it emerges out of the prism. Critical angle of the glass is 42$^\circ$.