List of practice Questions

A proton, a neutron, an electron and an α-particle have same energy. If λ_p, λ_n, λ_e and λ_α are the de Broglie’s wavelengths of proton, neutron, electron and α particle respectively, then choose the correct relation from the following:

Which of the following figure represents the variation of $ln (\frac{R}{R_0})$ with $ln\ A$?
(if $R$ = radius of a nucleus and $A$ = its mass number)

If n represents the actual number of deflections in a converted galvanometer of resistance G and shunt resistance S. Then the total current I when its figure of merit is K will be

A baseband signal of 3.5 MHz frequency is modulated with a carrier signal of 3.5 GHz frequency using amplitude modulation method. What should be the minimum size of antenna required to transmit the modulated signal?

A Carnot engine whose heat sinks at 27°C, has an efficiency of 25%. By how many degrees should the temperature of the source be changed to increase the efficiency by 100% of the original efficiency?

A parallel plate capacitor is formed by two plates each of area 30p cm² separated by 1 mm. A material of dielectric strength 3.6 × 10⁷ Vm^–1 is filled between the plates. If the maximum charge that can be stored on the capacitor without causing any dielectric breakdown is 7 × 10^–6 C, the value of dielectric constant of the material is : [$\frac{1}{4πε0}$=9×10⁹$Nm^2C^{-2}$]

The magnetic field at the centre of a circular coil of radius r, due to current I flowing through it, is B. The magnetic field at a point along the axis at a distance $\frac{r}{2}$ from the centre is :

Two metallic blocks M₁and M₂of the same cross-section area are connected (as shown in the figure). If the thermal conductivity of M₂ is K then the thermal conductivity of M₁ will be : [Assume steady state heat conduction]

A transistor is used in common-emitter mode in an amplifier circuit. When a signal of 10 mV is added to the base-emitter voltage, the base current changes by 10 mA and the collector current changes by 1.5 mA. The load resistance is 5 kW. The voltage gain of the transistor will be ___.

A projectile is launched at an angle ‘α’ with the horizontal with a velocity $20$ $ms^{–1}$. After $1 0$ $s$, its inclination with horizontal is ‘β’. The value of tanβ will be ($g$ = $10$ $ms^{–2}$).

As shown in the figure an inductor of inductance 200 mH is connected to an AC source of emf 220 V and frequency 50 Hz. The instantaneous voltage of the source is 0 V when the peak value of current is$\sqrt{\frac{a}{\pi}}$.The value of a is ___

Sodium light of wavelengths 650 nm and 655 nm is used to study diffraction at a single slit of aperture 0.5 mm. The distance between the slit and the screen is 2.0 m. The separation between the positions of the first maxima of diffraction pattern obtained in the two cases is _____ × 10^–5 m.

As per the given figure, two blocks each of mass $250 \,g$ are connected to a spring of spring constant $2 \,Nm ^{-1}$ If both are given velocity $v$ in opposite directions, then maximum elongation of the spring is :

A monkey of mass $50 \,kg$ climbs on a rope which can withstand the tension $(T)$ of $350 \,N$ If monkey initially climbs down with an acceleration of $4\, m / s ^2$ and then climbs up with an acceleration of $5 \,m / s ^2$ Choose the correct option $\left( g =10\, m / s ^2\right)$

If $Z=\frac {A^2B^3}{C^4},$ then the relative error in Z will be

Identify the pair of physical quantities that have same dimensions :

$\vec A$ is a vector quantity such that
$|\vec A|$ = non-zero constant.
Which of the following expression is true for $\vec A$?

The distance between Sun and Earth is R. The duration of year if the distance between Sun and Earth becomes 3R will be :

A stone of mass m tied to a string is being whirled in a vertical circle with a uniform speed. The tension in the string is

Two identical charged particles each having a mass 10 g and charge $2.0 × 10^{–7}$ C are placed on a horizontal table with a separation of L between them such that they stay in limited equilibrium. If the coefficient of friction between each particle and the table is $0.25$, find the value of L. [Use g = $10$ $ms^{–2}$]

Which of the following relations is true for two unit vector $\hat A$ and $\hat B$ making an angle θ to each other?

A Carnot engine takes 5000 kcal of heat from a reservoir at 727°C and gives heat to a sink at 127°C. The work done by the engine is

Two massless springs with spring constant 2 k and 9 k, carry 50 g and 100 g masses at their free ends. These two masses oscillate vertically such that their maximum velocities are equal. Then, the ratio of their respective amplitude will be

What will be the most suitable combination of three resistors A = 2 Ω, B = 4 Ω, C = 6 Ω so that $(22/3)$ Ω is equivalent resistance of combination?

The soft-iron is a suitable material for making an electromagnet. This is because soft-iron has