List of top Physics Questions

A simple pendulum starts oscillating simple harmonically from its mean position (\(x = 0\)) with amplitude ' \(a\) ' and periodic time ' \(T\) '. The magnitude of velocity of pendulum at \(x = \frac{a}{2}\) is

Resolving power of a telescope can be increased by increasing

The ratio of the total energy of the (2^{nd}) orbit electron for the hydrogen atom ((^{1}H)) to that of a helium ion ((He^{+})) is :

A star radiates heat as a black body at temperature ' (T) '. The total radiant energy per unit area received at a distance ' (R) ' from the centre of a star of radius ' (r) ' is : ((\sigma =) Stefan's constant)

The magnetic field ((B)) inside a long solenoid carrying current ' (i) ' with an iron core is (( \mu_0 =) vacuum permeability, (\chi =) susceptibility)

An organ pipe closed at one end has fundamental frequency of (1500 Hz). The maximum number of overtones generated by this pipe which a normal person can hear is (Normal man hears up to (19.5 kHz))

A gas having (\gamma = \frac{5}{2}) and volume (360 c.c.) is suddenly compressed to (90 c.c.) If initial pressure is (P), then final pressure will be

A particle of mass \(200 \text{ g}\) is executing S.H.M. of amplitude \(0.2 \text{ m}\). At mean position, K.E. is \(16 \times 10^{-3} \text{ J}\). The equation of motion is:

An inductor of ((\frac{100}{\pi}) mH), capacitor of capacitance ((\frac{10^{-3}}{2\pi}) F) and resistance of (10 \Omega) are connected in series with an AC voltage source of (110 V), (50 Hz) supply. The tangent of the phase angle ' (\phi) ' between voltage and current is

A charge is uniformly distributed on the surface of a spherical rubber balloon. As it is blown up, the total electric flux coming out of the surface

Three rods of same mass are placed as shown in figure. The co-ordinates of centre of mass of the system are

A liquid drop splits into \(729\) identical spherical drops. If \(E\) is the original energy and \(U\) is the total resulting energy , then \(E/U = 1/x\). The value of \(x\) is.

Two vectors \(a\hat{i} + b\hat{j} + \hat{k}\) and \(2\hat{i} - 3\hat{j} + 4\hat{k}\) are perpendicular. When \(3a + 2b = 7\) , the ratio \(a/b\) is \(x/2\). The value of \(x\) is.

A coil of area \(3 \text{ m}^{2}\) is at right angles to a magnetic field of \(0.05 \text{ Wb/m}^{2}\). If the field is decreased to \(20%\) of its value in \(10 \text{ s}\) , the induced e.m.f. is.

Three immiscible transparent liquids with indices \(3/2\), \(4/3\) and \(6/5\) are arranged one above the other. The depths are \(3 \text{ cm}\), \(4 \text{ cm}\) and \(6 \text{ cm}\) respectively. The apparent depth of the vessel is.

A physical quantity ' \(X\) ' is related to four quantities as \(X = a^2 b^3 c^{5/2} d^{-2}\). The percentage error in 'a', 'b', 'c' and 'd' are \(1%\), \(2%\), \(2%\) and \(4%\) respectively. The percentage error in ' \(X\) ' is.

All the springs in fig. (a), (b) and (c) are identical, each having force constant \(K\). Mass \(m\) is attached to each system. If \(T_{a}\), \(T_{b}\) and \(T_{c}\) are the time periods of oscillations in fig. (a), (b) and (c) respectively, then:

In metre-bridge experiment the balance point is obtained if the gaps are closed by \(2 \Omega\) and \(3 \Omega\). A shunt of \(x \Omega\) is added to \(3 \Omega\) resistor to shift the balance point by \(22.5 \text{ cm}\). The value of \(x\) is.

A radioactive element having half-life (30 min) is undergoing beta decay. The fraction of radioactive element remains undecayed after (90 min) will be

The potential difference across the (4 \muF) capacitor in the following circuit is

The relation between efficiency ((\eta)) of Carnot engine and coefficient of performance ((\beta)) of refrigerator is

A black body has maximum wavelength ' (\lambda_{m}) ' at temperature (2000 K). Its maximum wavelength at (3000 K) will be

The moment of inertia of a thin uniform rod of mass ' (M) ' and length ' (L) ', about an axis perpendicular to length and at a distance ' (L/4) ' from one end is

A wire of length '(L)' carries a current '(I)'. If the wire is turned into a square coil of single turn, the maximum magnitude of the torque in a given magnetic field ((\vec{B})) is

A photosensitive surface has work function (\phi). If photon of energy (3\phi) falls on this surface, the electron comes out with maximum velocity of (4 \times 10^6 m/s). When photon energy is increased to (7\phi) then maximum velocity will be