List of practice Questions

The ratio of energies of photons produced due to transition of electron of hydrogen atom from its (i) second to first energy level and (ii) highest energy level to 2\(^\text{nd}\) level is respectively
If the angle of dip at places A and B are 30° and 45° respectively, the ratio of horizontal component of earth's magnetic field at A to that at B will be
When tension \( T \) is applied to a sonometer wire of length \( \ell \), it vibrates with the fundamental frequency \( n \). Keeping the experimental setup same, when the tension is increased by 8 newton, the fundamental frequency becomes three times the earlier fundamental frequency (\( n \)). The initial tension applied to the wire in newton was
The damping force of an oscillator is directly proportional to the velocity. The unit of constant of proportionality is
As we go from the equator of the earth to pole of the earth, the value of acceleration due to gravity
The length of solenoid is \( \ell \) whose windings are made of material of density \( D \) and resistivity \( Q \). The winding resistance is \( R \). The inductance of solenoid is
Refractive index of the medium is \( \mu \) and wavelength is \( \lambda \), then which of the following proportionality relation is correct?
In communication system, a repeater is used to extend the range of transmission. It is the combination of
The x, y components of vector \( \vec{P} \) have magnitudes 1 and 3 and the x, y components of resultant of \( \vec{P} \) and \( \vec{Q} \) have magnitudes 5 and 6 respectively. What is the magnitude of \( \vec{Q} \)?
A sonometer wire under suitable tension having specific gravity \( Q \), vibrates with frequency \( n \) in air. If the load is completely immersed in water the frequency of vibration of the wire will become
Five capacitors each of capacity \( C \) are connected as shown in the figure. If their resultant capacity is 2\mu F, then the capacity of each condenser is
There are four convex lenses \( L_1 \), \( L_2 \), \( L_3 \), and \( L_4 \) of focal length 2, 4, 6, and 8 cm respectively. Two of these lenses form a telescope of length 10 cm and magnifying power 4. The objective and eye lenses are respectively
Two wires of different materials have same length \( L \) and same diameter \( d \). The second wire is connected at the end of the first wire and forms one single wire of double the length. This wire is subjected to stretching force \( F \) to produce the elongation \( \Delta L \). The two wires have
An obstacle is moving towards the source with velocity \( v \). The sound is reflected from the obstacle. If \( c \) is the speed of sound and \( \lambda \) is the wavelength, then the wavelength of the reflected wave \( \lambda_r \) is
A spherical rubber balloon carries a charge, uniformly distributed over the surface. As the balloon is blown up and increases in size, the total electric flux coming out of the surface
A step-up transformer has 300 turns of primary winding and 450 turns of secondary winding. A primary is connected to 150 volt and the current flowing through it is 9A. The current and voltage in the secondary are
A diatomic gas undergoes adiabatic change. Its pressure \( P \) and temperature \( T \) are related as \( P \propto T^x \), where \( x \) is
A ray of light travelling through glass of refractive index \( \sqrt{2} \) is incident on glass-air boundary at an angle of incidence 45°. If refractive index of air is 1, then the angle of refraction will be
Which of the following instruments is \textit{NOT} a direct reading instrument?
A transistor has a voltage gain \( A \). If the amount \( \beta A \) of its output is applied to the input of the transistor, then the transistor becomes oscillator when
An \( \alpha \) particle of energy 10 eV is moving in a circular path in a uniform magnetic field. The energy of proton moving in the same path and same magnetic field will be [mass of \( \alpha \) particle = 4 times mass of proton]
Two spherical black bodies of radius \( r_1 \) and \( r_2 \) with surface temperature \( T_1 \) and \( T_2 \) respectively, radiate the same power, then \( \frac{r_1}{r_2} \) is
The graph of kinetic energy against the frequency \( v \) of incident light is as shown in the figure. The slope of the graph and intercept on X-axis respectively are
A simple pendulum of length \( \ell \) has a bob of mass \( m \). It executes S.H.M. of small amplitude \( A \). The maximum tension in the string is
The magnetic susceptibility of a paramagnetic material at \( -73^\circ \text{C} \) is \( 0.0075 \). Its value at \( -173^\circ \text{C} \) will be