List of top Physics Questions

Which of the following figure represents forward bias diode?

Energy of the incident photons on the metal surface is initially \(4 \text{ W}\) and then \(6 \text{ W}\) where \(W\) is the work function of that metal. The ratio of velocities of emitted photoelectrons is

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

In YDSE, the intensity where path difference is (\frac{\lambda}{4}) is (\frac{K}{4}). The intensity at a point when path difference is ' (\lambda) ' will be

The distance between two consecutive points with phase difference of \(45^{\circ}\) in a wave of frequency \(300 \text{ Hz}\) is \(4.0 \text{ m}\). The velocity of the travelling wave is (in \( \text{km/s} \))

A coil having ' \(N\) ' turns and resistance ' \(R \Omega\) ' is connected to a galvanometer of resistance ' \(6 \text{ R } \Omega\) '. The magnetic flux linked with this coil changes from \(\phi_1\) weber to \(\phi_2\) weber in time ' \(t\) ' second. The induced current in the circuit is

When LED is manufactured by using aluminium gallium arsenide (AlGaAs), it emits

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 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)

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 :

Resolving power of a telescope can be increased by increasing

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 circular coil has radius ' \(R\) '. The distance from centre on axis where induction is \(1/27\) th of its value at centre is.

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:

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.

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.

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.

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.

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:

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 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.