List of practice Questions

An amorphous solid $(X)$ burns in air to form a gas $(Y)$ which turns lime water milky. This gas decolourises aqueous solution of acidified $KMnO_4$. Gas $(Y)$ reacts with oxygen to give another gas $(Z)$ which is responsible for acid rain. $X$, $Y$ and $Z$ are
An amplifier has a voltage gain of $100$. The voltage gain in $dB$ is
An anti-aircraft gun takes a maximum of four shots at an enemy plane moving away from it. The probability of hitting the plane at the first, second, third and fourth shot are 0.4, 0.3, 0.2 and 0.1 respectively. The probability that the gun hits the plane is:
An alternating emf given by $V = V_0 \, \sin \,\omega t$ has peak value 10 volt and frequency 50 Hz. The instantaneous emf at $t=\frac{1}{600}s$ is
An alternating emf is applied across a parallel combination of a resistance R, capacitance C and an inductance L. If $I_R\, , I_L$ and $I_C$ are the currents through R, L and C respectively, then the diagram which correctly represents the phase relationship among $I_R,\, I_L,\, I_C$ and source emf $\varepsilon$, is given by
An alternating supply of $220\,V$ is applied across a circuit with resistance $22\,\Omega$ and impedance $44\,\Omega$. The power dissipated in the circuit is
An aluminium rod has a breaking strain 0.2%. The minimum cross-sectional area of the rod in $m^2$ in order to support a load of $10^4N$ is if Youngs modulus is $7 \times 10^9Nm^{-2}$
An alkyl halide, $RX$ reacts with $KCN$ to give propane nitrile. $RX$ is
An alternating current generator has an internal resistance $R_g$ and an internal reactance $X_g$. It is used to supply power to a passive load consisting of a resistance $R_g$ and a reactance $X_L$. For maximum power to be delivered from the generator to the load, the value of $X_L$ is equal to
An aircraft executes a horizontal loop at a speed of $720\, km$ $h^{-1}$ with its wings banked at $15^?$. What is the radius of the loop? (Take $g=10\, m s^{-2}, tan \,15^{\circ}=0.27$)
An alcohol $(A)$ on dehydration gives $(B)$ which adds bromine molecule to give $(C). (C)$ on heating with sodamide gives $(D)$ which on hydration in the presence of $Hg^{++}/H_{2}SO_{4}$ gives $(E). E$ on reduction by lithium aluminium hydride gives $(A). (E)$ is also obtained on dry distillation of calcium salt of acetic acid. How many enolisable proton present in the product $(E)$?
An aldehyde on oxidation gives
An air bubble in a glass slab (n = 1.5) is 5 cm deep when viewed from one face and 2 cm deep when viewed from the opposite face. The thickness of the slab is
An air bubble in a glass sphere $(\mu = 1.5)$ is situated at a distance $3\, cm$ from a convex surface of diameter $10\, cm$. At what distance from the surface will the bubble appear?
An air cored solenoid with length $20\, cm$, area of cross section $20\, cm^{2}$ and number of turns $400$ carries a current $2\, A$. The current is suddenly switched off within $10^{-3}\, s$. The average back emf induced across the ends of the open switch in the circuit is (ignore the variation in magnetic field near the ends of the solenoid)
An acidified solution of potassium permanganate oxidizes
An aeroplane flying horizontally with a speed of $360\,km\,h^{-1}$ releases a bomb at a height of $490\,m$ from the ground. If $g = 9.8\,m \,s^{-2}$, it will strike the ground at
An ac source of angular frequency $\omega$ is fed across a resistor R and a capacitor C in series. The current registered is I. If now the frequency of source is changed to $\omega/3$ (but maintaining the same voltage), the current in the circuit is found to be halved. Calculate the ratio of reactance to resistance at the original frequency $\omega$
Amrita Devi Bishnoi Wildlife Protection Award is for the individuals or communities from rural areas that have shown extraordinary courage in
An a.c. generator consists of a coil of $100$ turns and cross-sectional area of $3 \,m^{2}$, rotating at a constant angular speed of $60$ radian/sec in a uniform magnetic field of $0.04 \,T$. The resistance of the coil is $500$ ohm. What is the maximum power dissipation in the coil?
An A.C. is given by equation $I = I_1\cos\,\omega t + I_2\,\sin \,\omega t$. The r.m.s. value of current is given by
An A.P., a G.P. and a H.P. have the same first and last terms and the same odd numbers of terms, the middle terms of the three series are in
Amphoteric oxide among the following is -
Amphoteric oxides of Mn and Cr are
Amongst vertebrates, the species diversity is the maximum in