List of practice Questions

A Williamson's synthesis of ethers is an example of
A wire has a mass $(0.3 \pm 0.003)\, g$, radius $(0.5 \pm 0.005)\,cm$ and length $(6 \pm 0.06) \,cm$. The maximum percentage error in the measurement of its density is
A well stoppered thermos flask contains some icecubes. This is an example of
A wheel completes $2000$ revolutions to cover the $9.5\,km$ distance, then the diameter of the wheel is
A water tank standing on the floor has two small holes vertically one above the other punched on one side. The holes are $h_1$ cm and $h_2$ cm above the floor. How high does water stand in the tank when the jets from the holes hit the floor at the same point ?
A weather balloon filled with hydrogen at 1 atm and 27$^\circ$C has volume equal to 1200 litres. On ascending, it reaches a place where temperature is -23$^\circ$C and pressure is 0.5 atm. The volume of the balloon is
A weight $w$ is suspended from, the mid-point of a rope, whose ends are at the same level. In order to make the rope perfectly horizontal, the force applied to each of its ends must be
Which of the following contribute towards photochemical smog formation?
Saline soil contains
Most hazardous metal pollutant of automobile exhausts is
Taj may be destroyed by
Ultraviolet radiation from sun causes a reaction that produces
Which of the following is/are the main agents of soil erosion?
Classical Smog is also known as
Increased asthmatic attacks in certain seasons are related to
Ozone layer of upper atmosphere is being destroyed by
Which one of the following dissolves more rapidly in blood haemoglobin than oxygen ?
A vibration magnetometer consists of two identical bar magnets placed one over the other such that they are mutually perpendicular and bisect each other. The time period of oscillations of combination in a horizontal magnetic field is 4s. If one of the magnets is removed, then the period of oscillations of the other in the same field is
A watch glass containing some powdered substance is placed between the pole pieces of a magnet. Deep concavity is observed at the centre. The substance in the watch glass is (assume poles are far)
A water proofing agent changes the angle of contact from
A vessel contains two immiscible liquids of density $\rho_{1}=1000 \, kg \, m^{-3}$ and $\rho_{2}=1500 \, kg \, m^{-3}$. A solid block of volume $V=10^{-3} \, m^{3}$ and density $d=800 \, kg \, m^{-3}$ is tied to one end of a string and other end is tied to the bottom of the vessel. The block is immersed with $2/5^{th}$ of its volume in the liquid of higher density and $3/5^{th}$ in the liquid of lower density. The entire system is kept in an elevator which is moving upwards with an acceleration of $a=g/2$. The tension in the string is (Take $g=10\, m\, s^{-2}$).
A vessel contains two non-reactive gases neon (monatomic) and oxygen (diatomic). The ratio of their partial pressures is $3 : 2$. The ratio of number of molecules is
A vessel has $6\,g$ of oxygen at pressure $P$ and temperature $400\, K$. A small hole is made in it so that oxygen leaks out. How much oxygen leaks out if the final pressure is $\frac{P}{2}$ and temperature $300\, K$ ?
A vibrating tuning fork of frequency $\upsilon$ is placed near the open end of a long cylindrical tube. The tube has a side opening and is also fitted with a movable reflecting piston. As the piston is moved through $8.75 \,cm$, the intensity of sound changes from a maximum to minimum. If the speed of sound is $350 \,m \,s^{-1}$, then $\upsilon$ is
A vehicle travels half the distance $ L $ with speed $ v_1 $ and the other half with speed $ v_2 $ , then its average speed is