biology Questions

111 Questions available

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A photon and an electron (mass $m$) have the same energy $E$. The ratio ($\lambda_{\text{photon}}/\lambda_{\text{electron}}$) of their de Broglie wavelengths is ($c$ is the speed of light)

Easy

A constant voltage of $50\text{ V}$ is maintained between the points $A$ and $B$ of the circuit shown in the figure. The current through the branch $CD$ of the circuit is:

Easy

An electric dipole with dipole moment $5 \times 10^{-6}\text{ Cm}$ is aligned with the direction of a uniform electric field of magnitude $4 \times 10^5\text{ N/C}$. The dipole is then rotated through an angle of $60^\circ$ with respect to the electr

Easy

De-Broglie wavelength of an electron orbiting in the $n = 2$ state of hydrogen atom is close to (Given Bohr radius $= 0.052\text{ nm}$)

Easy

A wire of resistance R is cut into 8 equal pieces. From these pieces two equivalent resistances are made by adding four of these together in parallel. Then these two sets are added in series. The net effective resistance of the combination is:

Easy

A body weight $48\text{ N}$ on the surface of the earth. The gravitational force experienced by the body due to the earth at a height equal to one-third the radius of the earth from its surface is:

Easy

The radius of Martian orbit around the Sun is about $4\text{ times}$ the radius of the orbit of Mercury. The Martian year is $687\text{ Earth days}$. Then which of the following is the length of 1 year on Mercury?

Easy

A particle of mass $m$ is moving around the origin with a constant force $F$ pulling it towards the origin. If Bohr model is used to describe its motion, the radius $r$ of the $n^{\text{th}}$ orbit and the particle's speed $v$ in the orbit depend on

Easy

A container has two chambers of volumes $V_1 = 2\text{ litres}$ and $V_2 = 3\text{ litres}$ separated by a partition made of a thermal insulator. The chambers contains $n_1 = 5$ and $n_2 = 4\text{ moles}$ of ideal gas at pressures $p_1 = 1\text{ atm}

Easy

#10

A model for quantized motion of an electron in a uniform magnetic field $B$ states that the flux passing through the orbit of the electron is $n(h/e)$ where $n$ is an integer, $h$ is Planck's constant and $e$ is the magnitude of electron's charge. Ac

Easy

#11

The Sun rotates around its centre once in 27 days. What will be the period of revolution if the Sun were to expand to twice its present radius without any external influence? Assume the Sun to be a sphere of uniform density.

Easy

#12

To an ac power supply of 220 V at 50 Hz, a resistor of 20 Ω, a capacitor of reactance 25 Ω and an inductor of reactance 45 Ω are connected in series. The corresponding current in the circuit and the phase angle between the current and the voltage is,

Easy

#13

In a certain camera, a combination of four similar thin convex lenses are arranged axially in contact. Then the power of the combination and the total magnification in comparison to the power () and magnification () for each lens will be, respectivel

Easy

#14

The output of the given logic implementation is similar to the output of an/a ________gate.

Easy

#15

A bob of heavy mass m is suspended by a light string of length l. The bob is given a horizontal velocity v₀ as shown in figure. If the string gets slack at some point P making an angle θ from the horizontal, the ratio of the speed v of the bob at poi