List of practice Questions

A 150 watt bulb emits light of wavelength 6600 $?$ and only 8% of the energy is emitted as light. How many photons are emitted by the bulb per second?
A spherical balloon is being inflated at the rate of $35\, cc$ per minute, When its radius is $7\, cm$, its surface area increases at the rate of
$aP + bQ \to $ Products, when $[P]$ is doubled keeping $[Q]$ constant rate increases $2$ times, when $[P]$ is constant and $[Q]$ is doubled, rate increases four times. The overall order is
Einstein was awarded Nobel prize for his work in
If the circle $x^2+y^2+2\,gx+2fy+=0,$ and $x^2+y^2+2g'x+2f'y$ touch each other, then
If the line px + qy = 0 coincides with one of the lines given by $ax^2 + 2hxy + by^2 = 0$, then
In the following sets of ions, which one is not isoelectronic with the rest of the species? $ { O^{2-}, F^- , Na, Mg^{2+}, Al^{3+}, Ne} $
One second is defined as
Schottky defect in crystals is observed when
The radius of an atom is $300\,pm$. If it crystallizes in a face-centered cubic lattice, length of the edge of the unit cell is
The subtangent at $x = \pi/2$ on the curve $y = x \sin x $ is
The unstable intermediate dichlorocarbene $ {[:CCl_2]}$ is formed during
The value of $\sin \left[\cot^{-1}\{{\cos(tan^{-1}\,x)\}}\right]$ is
Van't Hoff factors of equimolal solutions of sodium chloride, barium chloride and glucose in water are
Vapour pressure of water at $293\, K$ is $17.535\, mm \,Hg$. The vapour pressure of water at $293 \,K$ containing $25 \,g$ of glucose dissolved in $450\, g$ of water is
When $2$-bromopentane is heated with alcoholic solution of potassium hydroxide, the major product obtained is
A crystalline solid has $A^-$ ions at the corners and face centres whereas $B^+$ ions are at the body centre and edge centres of the unit cell. The simplest formula of the compound will be
An orbital with $n = 3, l = 1$ is designated as
On an average, a human heart is found to beat $72$ times a minute. Its frequency and period are
A proton and helium nucleus are shot into a magnetic field at right angles to the field with same kinetic energy. Then the ratio of their radii is
Which one of the following represents uniform motion ?
A concave mirror forms an enlarged, erect, virtual image of an object, only when the object is placed
Among $2$-chloropropanoic acid, $3$-chloropropanoic acid, $2,2$-dichloroacetic acid and propanoic acid the $K_a$ values will be in the order,
Among the following compounds, the only one which is not an. artificial sweetening agent is
An aeroplane is flying horizontally with a velocity of $360\, km\, h^{-1}$. The distance between the tips of the wings of the aeroplane is $50\, m$. The vertical component of the earth's magnetic field is $4 \times 10^{-4} \, Wb \, m^{-2}$. The induced e.m.f. is