List of top Physics Questions

Two masses \(M_1\) and \(M_2\) are tied together at the two ends of a light inextensible string that passes over a frictionless pulley. When the mass \(M_2\) is twice that of \(M_1\), the acceleration of the system is \(a_1\). When the mass \(M_2\) is thrice that of \(M_1\), the acceleration of the system is \(a_2\). The ratio \(\frac{a_1}{a_2}\) will be

A thin circular ring of mass M and radius R is rotating with a constant angular velocity 2 rad s^–1 in a horizontal plane about an axis vertical to its plane and passing through the center of the ring. If two objects each of mass m be attached gently to the opposite ends of a diameter of ring, the ring will then rotate with an angular velocity (in rad s^–1)

The area of cross section of the rope used to lift a load by a crane is \(2.5 × 10^{–4}\) \(m^2\). The maximum lifting capacity of the crane is \(10\) metric tons. To increase the lifting capacity of the crane to \(25\) metric tons, The required area of cross section of the rope should be

The variation of acceleration due to gravity (g) with distance (r) from the center of the earth is correctly represented by
(Given R = radius of earth)

The typical transfer characteristics of a transistor in CE configuration is shown in figure. A load resistor of \(2\) \(kΩ\) is connected in the collector branch of the circuit used. The input resistance of the transistor is \(0.50\) \(kΩ\). The voltage gain of the transistor is ________.

Time period of a simple pendulum in a stationary lift is ‘T’. If the lift accelerates with \(\frac{g}{6}\) vertically upwards then the time period will be (Where g = acceleration due to gravity)

A uniform heavy rod of mass \(20\) kg, cross sectional area \(0.4\) \(m^2\) and length \(20\) \(m\) is hanging from a fixed support. Neglecting the lateral contraction, the elongation in the rod due to its own weight is \(x × 10^{–9}\) \(m\). The value of \(x\) is _____(Given Young’s modulus \(Y = 2 × 10^{11} Nm^{–2}\)and g = \(10\; ms^{–2})\)

A velocity selector consists of electric field \(\overrightarrow E=E\hat K\) and magnetic field \(\overrightarrow B=B\hat j\) with \(B = 12 \;mT\). The value of E required for an electron of energy \(728\) \(eV\) moving along the positive x-axis to pass undeflected is (Given, mass of electron = \(9.1 × 10^{–31}\) kg)

The efficiency of a Carnot’s engine, working between steam point and ice point, will be

A thermally insulated vessel contains an ideal gas of molecular mass M and ratio of specific heats 1.4. Vessel is moving with speed ν and is suddenly brought to rest. Assuming no heat is lost to the surrounding and vessel temperature of the gas increases by(R = universal gas constant

In a coil of resistance \(8Ω\), the magnetic flux due to an external magnetic field varies with time as \(Φ=\frac{2}{3}(9−t^2)\).The value of total heat produced in the coil, till the flux becomes zero, will be _ \(J\).

A potentiometer wire of length 300 cm is connected in series with a resistance 780 Ω and a standard cell of emf 4V. A constant current flows through potentiometer wire. The length of the null point for cell of emf20 mV is found to be 60 cm. The resistance of the potentiometer wire is _____ Ω.

Mass numbers of two nuclei are in the ratio of \(4 : 3\). Their nuclear densities will be in the ratio of

For the network shown below, the value of V_B– V_A is ________V.

If \(\overrightarrow A=(2\hat i+3\hat j−\hat k)m\) and \(\overrightarrow B=(\hat i+2\hat j+2\hat k)m\). The magnitude of component of vector \(\overrightarrow A\) along vector \(\overrightarrow B\) will be ______\(m\).

Two concentric circular loops of radii \(r_1 = 30\) cm and \(r_2 = 50\) cm are placed in \(X–Y\) plane as shown in the figure. \(A\) current \(I = 7 \;A\) is flowing through them in the direction as shown in figure. The net magnetic moment of this system of two circular loops is approximately

Two lighter nuclei combine to from a comparatively heavier nucleus by the relation given below: \(^2_1X+^2_1X=^4_2Y\). The binding energies per nucleon for, \(^2_1X\) and \(^4_2Y\) are 1.1 MeV and 7.6 MeV respectively. The energy released in the process is ______ MeV.

A parallel beam of light is allowed to fall on a transparent spherical globe of diameter 30 cm and refractive index 1.5. The distance from the centre of the globe at which the beam of light can converge is________ mm.

The radius of gyration of a cylindrical rod about an axis of rotation perpendicular to its length and passing through the center will be_________m. Given the length of the rod is \(10\sqrt3\; m\).

A light ray is incident at an incident angle θ₁ on the system of two plane mirrors M₁ and M₂ having an inclination angle 75° between them (as shown in figure). 
After reflecting from mirror M₁ it gets reflected back by the mirror M₂ with an angle of reflection 30°. The total deviation of the ray will be ________ degree.

A ball of mass 0.5 kg is dropped from the height of 10 m. The height, at which the magnitude of velocity becomes equal to the magnitude of acceleration due to gravity, is ___ m.
[Use g = 10 m/s²]

The elongation of a wire on the surface of the earth is 10^–4m. The same wire of same dimensions is elongated by 6 × 10^–5m on another planet. The acceleration due to gravity on the planet will be ___ ms^–2. (Take acceleration due to gravity on the surface of earth = 10 ms^–2)

A body of mass m is projected with velocity λv_e in vertically upward direction from the surface of the earth into space. It is given that v_e is escape velocity and λ< 1. If air resistance is considered to be negligible, then the maximum height from the centre of earth, to which the body can go, will be:
(R : radius of earth)

Two capacitors having capacitance C₁ and C₂ respectively are connected as shown in figure. Initially, capacitor C₁ is charged to a potential difference V volt by a battery. The battery is then removed and the charged capacitor C₁ is now connected to uncharged capacitor C₂ by closing the switch S. The amount of charge on the capacitor C₂, after equilibrium, is