List of top Physics Questions

Two waves represented by $y\, =\, asin(\omega\,t - kx)$ and $y \,= \,acos(\omega\,t - kx)$ are superposed. The resultant wave will have an amplitude

Two parallel long wires A and B carry currents $i_1$ and $i_2 (< i_1)$. When $i_1$ and $i_2$ are in the same direction, the magnetic field at a point mid way between the wires is $10 \,\mu\,T$. If $i_2$ is reverse the field becomes $30\, \mu T$. The ratio $i_1/i_2$ is

Two conducting circular loops of radii $R_{1}$ and $R_{2}$ are placed in the same plane with their centres coinciding. If $R_{1} >\, R_{2}$ the mutual inductance $M$ between them will be directly proportional to

Two capacitors of $10\, PF$ and $20\, PF$ are connected to $200 \,V$ and $100\, V$ sources respectively. If they are connected by the wire, what is the common potential of the capacitors ?

Two amplifiers are connected one after the other in series (cascaded). The first amplifier has a voltage gain of $10$ and the second has a voltage gain of $20$. If the input signal is $0.01\, volt$, what is the output $ac$ signal ?

Three charges $-q, +Q$ and $-q$ are placed at equal distances along a straight line. If the total $P.E.$ of the system is zero, the ratio $ \frac{Q}{q} $ becomes

The oscillation of a body on a smooth horizontal surface is represented by the equation, $ X = A \cos \, ( \omega \, t)$ where X = displacement at time t $ \omega$ = frequency of oscillation Which one of the following graphs shows correctly the variation a with $t$ ?

The force between two parallel current carrying wires is independent of

The diameter of the plate of a parallel plate condenser is $6\,cm$. If its capacity is equal to that of a sphere of diameter $200\, cm$, the separation between the plates of the condenser is

Nicol prism is made up of

If the length and area of cross-section of a conductor are doubled, then its resistance will be

The ratio of inertial mass to gravitational mass is equal to one. The inertial mass and gravitational mass of a body are equivalent.

Magnetic field interacts with a moving charge and not with a stationary charge. A moving charge produces a magnetic field.

According to kinetic theory of gases, molecules of a gas behave like

A triply ionized beryllium ($Be^{+++}$) has the same orbital radius as the ground state of hydrogen. Then the quantum state $n$ of $Be^{3+}$ is

Two ideal batteries of $emf V _{1}$ and $V _{2}$ and three resistances $R _{1}, R _{2}$ and $R _{3}$ are connected as shown in the figure. The current in resistance $R _{2}$ would be zero if

In a common emitter transistor amplifier an increase of $50 \,\mu A$ in the base current causes an increase of $1 \,mA$ in the collector current. The change in emitter current is

If $force (F)$, $velocity (V)$ and $time (T)$ are taken as fundamental units, then the dimensions of mass are

Considering normal incidence of ray, the equivalent refractive index of combination of two slabs shown in figure is:

A particle of charge q and mass m starts moving from the origin under the action of an electric field $\vec{E}=E_{0} \hat{i} $and $\vec{B}=B_{0} \hat{i}$ with a velocity $\vec{v}=v_{0} \hat{j}$ . The speed of the particle will become $\frac{\sqrt{5}}{2}v_{0}$ after a time

A particle moves along a curve of unknown shape but magnitude offeree $F$ is constant and always acts along tangent to the curve. Then,

A closely wound solenoid of $2000$ turns and area of cross-section $1.5 \times 10^{-4} m ^{2}$ carries a current of $2.0 A$. It is suspended through its center and perpendicular to its length, allowing it to turn in a horizontal plane in a uniform magnetic field $5 \times 10^{-2} T$, making an angle of $30^{\circ}$ with the axis of the solenoid. The torque on the solenoid will be

A block of mass 2 kg is placed on the floor. The coefficient of static friction is 0.4. If a force of 2.8 N is applied on the block parallel to the floor, the force of friction between the block and the floor is (g = 10 m s)

Figure shown a smooth inclined plane of inclination $\theta$ fixed in a car, $A$ sphere is set in pure rolling on the incline. For what value of a (the acceleration of car in horizontal direction) the sphere will continue pure rolling

A black body emits heat at the rate of $20\, W$. When its temperature is $727^{\circ} C$. Another black body emits heat at the rate of $15\, W$, when its temperature is $227^{\circ} C$. Compare the area of the surface of the two bodies, if the surrounding is at NTP.