List of top Physics Questions

The current in a conductor is expressed as I = 3t² + 4t³ , where I is in Ampere and t is in second. The amount of electric charge that flows through a section of the conductor during t = 1s to t = 2s is ____________ C.

Two conductors have the same resistances at \( 0^\circ \text{C} \) but their temperature coefficients of resistance are \( \alpha_1 \) and \( \alpha_2 \). The respective temperature coefficients for their series and parallel combinations are:

The value of net resistance of the network as shown in the given figure is :

Twelve wires, each having resistance \( 2 \, \Omega \), are joined to form a cube. A battery of \( 6 \, \text{V} \) emf is joined across points \( a \) and \( c \). The voltage difference between \( e \) and \( f \) is ______ \( \text{V} \).

In the given figure \( R_1 = 10 \, \Omega \), \( R_2 = 8 \, \Omega \), \( R_3 = 4 \, \Omega \), and \( R_4 = 8 \, \Omega \). The battery is ideal with an EMF of 12V.
The equivalent resistance of the circuit and the current supplied by the battery are respectively:

The equivalent resistance between A and B is:

A heater is designed to operate with a power of 1000 W in a 100 V line. It is connected in combination with a resistance of 10 \(\Omega\) and a resistance \(R\), to a 100 V mains as shown in the figure. For the heater to operate at 62.5 W, the value of \(R\) should be \(\dots\) \(\Omega\).

A potential divider circuit is connected with a dc source of 20 V, a light emitting diode of glow in voltage 1.8 V and a zener diode of breakdown voltage of 3.2 V. The length (PR) of the resistive wire is 20 cm. The minimum length of PQ to just glow the LED is …………. cm.

In the given circuit, the terminal potential difference of the cell is :

A wire of resistance R and radius r is stretched till its radius became r/2. If new resistance of the stretched wire is x R, then value of x is _________.

Choose the correct circuit which can achieve the bridge balance.

The following figure shows the variation of potential energy V (x) of a particle with distance x. The particle has:

A small sphere of mass m and radius R slides down the smooth surface of a large hemispherical bowl of radius R. If the sphere starts sliding from rest, the total kinetic energy of the sphere at the lowest point A of the bowl will be:

Consider the integral form of the Gauss's law in electrostatics:
\( \oint \oint \vec{E} \cdot d\vec{A} = \frac{Q}{\epsilon_0} \)
Which of the following statements are correct?

The electric field of a plane electromagnetic wave in a medium is given by

where c is the speed of light in free space. E field is polarized in the x −z plane. The speed of the wave is v in the medium. Then:

Two convex lenses (\(L_1\) and \(L_2\)) of equal focal length \(f\) are placed at a distance \(\frac{f}{2}\) apart. An object is placed at a distance \(4f\) to the left of \(L_1\) as shown in the figure. The final image is at:

A 2V cell is connected across the points A and B as shown in the figure. Assume that the resistance of each diode is zero in forward bias and infinity in reverse bias. The current supplied by the cell is:

A particle of mass \( m \) moves in one dimension under the action of a conservative force whose potential energy has the form \( U(x) = \frac{\alpha x}{x^2 + \beta^2} \), where \( \alpha \) and \( \beta \) are dimensional parameters. The angular frequency \( \omega \) of the oscillation is proportional to:

A metal plate of area 10^-2m² rests on a layer of castor oil, 2 × 10^-3m thick, whose viscosity coefficient is 1.55 Ns/m². The approximate horizontal force required to move the plate with a uniform speed of 3 × 10^-2ms^-1 is:

Two straight conducting plates form an angle θ where their ends are joined. A conducting bar in contact with the plates and forming an isosceles triangle with them, starts at the vertex at time t = 0 and moves with constant velocity v to the right as shown in the figure. A magnetic field B points out of the page. The magnitude of emf induced at t = 1 second will be:

Which of the following quantity has the dimension of length? (where \(h\) is Planck’s constant, \(m\) is the mass of electron and \(c\) is the velocity of light):

Let \( \theta \) be the angle between two vectors \( \vec{A} \) and \( \vec{B} \). If \( \hat{a}_\perp \) is the unit vector perpendicular to \( \vec{A} \), then the direction of \( \vec{B} - \vec{B} \sin \theta \hat{a}_\perp \) is:

The position vector of a particle of mass \(m\) moving with a constant velocity \(\mathbf{u}\) is given by \(\mathbf{r} = x(t)\hat{i} + b\hat{j}\), where \(b\) is a constant. At an instant, \(\mathbf{r}\) makes an angle \(\theta\) with the x-axis as shown in the figure. The variation of the angular momentum of the particle about the origin with \(\theta\) will be:

A small ball of mass m is suspended from the ceiling of a floor by a string of length L. The ball moves along a horizontal circle with constant angular velocity ω, as shown in the figure. The torque about the center (O) of the horizontal circle is:

In a single-slit diffraction experiment, the slit is illuminated by light of two wavelengths \(\lambda_1\) and \(\lambda_2\). It is observed that the 2nd order diffraction minimum for \(\lambda_1\) coincides with the 3rd diffraction minimum for \(\lambda_2\). Then: