List of practice Questions

What should be the length of antenna for a carrier wave of frequency \(6 \times 10^{8}\,\text{Hz}\)? (Given: velocity of light \(c = 3 \times 10^{8}\,\text{m/s}\))
Light travels through a glass plate of thickness \(d\) and refractive index \(\mu\). If \(c\) is the velocity of light in vacuum, the time taken by the light to travel the thickness of glass \(d\) is
A disc of moment of inertia \(I_1\) is rotating with angular velocity \(\omega_1\) about an axis perpendicular to its plane passing through its centre. If another disc of moment of inertia \(I_2\) about the same axis is gently placed over it, then the new angular velocity of the combined disc will be
Two monoatomic ideal gases \(A\) and \(B\) of molecular masses \(m_1\) and \(m_2\) respectively, are enclosed in separate containers kept at the same temperature. The ratio of speed of sound in gas \(A\) to that in gas \(B\) is given by
A small quantity of paramagnetic liquid is taken in a watch-glass and kept on two dissimilar magnetic poles. The liquid
The critical angle for a ray of light from glass to air is \( \theta \) and refractive index of glass with respect to air is \(n\). If a ray of light is incident from air to glass at an angle \( \theta \), then corresponding angle of refraction is
A particle is moving along a circular path of radius \(r\) with velocity \(v\). The magnitude of average acceleration after half revolution is
In an atom, two electrons complete three revolutions around the nucleus in circular orbit in time \(81t\) and \(192t\) respectively. The ratio of their radii will be (\(t\) is in second)
In Young’s double slit experiment, the angular width of a fringe is \(0.2^\circ\). If the entire apparatus is immersed in water of refractive index \(4/3\), the angular width of the fringe will be
A tuning fork of frequency 340 Hz is held vibrating at the open end of an empty measuring cylinder of length 100 cm. Water is then poured in slowly. What is the minimum height of water in the cylinder for which resonance will be obtained? (Given: Velocity of sound in air = 340 m/s, neglect end correction)
A black sphere has radius \(R\) whose rate of radiation is \(E\) at temperature \(T\). If the radius is made \( \dfrac{R}{3} \) and the temperature is made \(3T\), the new rate of radiation will be
A spray pipe has a cylindrical tube of radius \(R\). It has \(n\) small holes of radius \(r\) at one end. The liquid flows through the tube with velocity \(V\). The velocity of the liquid through the holes is
What is the energy stored per unit volume in vacuum, where the intensity of electric field is \(10^3 \, \text{V m}^{-1}\)?
(Given: \( \varepsilon_0 = 8.85 \times 10^{-12} \, \text{C}^2 \text{N}^{-1}\text{m}^{-2} \))
An ammeter and a microammeter are converted from the same galvanometer. The resistance required for the conversion is
A galvanometer of resistance \(20\,\Omega\) has a current sensitivity of 5 div/mA. The instrument has 50 divisions. It can be converted into a voltmeter reading up to 25 V by connecting a resistance of
In the differential equation of linear simple harmonic motion \(\displaystyle \frac{d^2x}{dt^2} + \omega^2 x = 0\), the term \( \omega^2 \) represents
A force of 26 N is acting on a body of mass 2 kg in the x-y plane. The force is directed at an angle \(\cos^{-1}\left(\frac{12}{13}\right)\) with the x-axis. The component of acceleration along y-axis is
An electron of charge \(e\) is revolving in a fixed orbit of radius \(r\) with frequency \(f\). Its magnetic dipole moment is
Which one of the following is a pair of isotones?
What is the percentage decrease in the weight of a body when it is taken to a height of 32 km from the surface of earth?
(Given: \( R = 6400 \, \text{km} \))
The 'Crenulation' effect on the cell wall is caused by ____and this effect is_____
The mechanism by which fluorides inhibit dental caries is
The principle of gas-liquid chromatography is _____.
The principle of liquid-liquid extraction is_____.
If two monosaccharides differ in their structure around a single carbon atom, they are called as