List of top Questions asked in KCET

An electric blub of 60 W, 120 V is to be connected to 220 V source. What resistance should be connected in series with the bulb, so that the bulb glows properly?

The electric current flowing through a given conductor varies with time as shown in the graph below. The number of free electrons which flow through a given cross-section of the conductor in the time interval 0 ≤ t ≤ 20s is

The natural logarithm of the activity R of a radioactive sample varies with time t as shown. At t=0, there are N₀ undecayed nuclei. Then N₀ is equal to [Take e²= 7.5]

A particle of mass 500 g is at rest. It is free to move along a straight line. The power delivered to the particle varies with time according to the following graph :
The momentum of the particle at t=5s is

In the circuit shown, the end A is at potential V₀ and end B is grounded. The electric current I indicated in the circuit is

A body has a charge of -3.2μC . The number of excess electrons it has is

A coil having 9 turns carrying a current produces magnetic filed B₁ at the centre. Now the coil is rewounded into 3 turns carrying same current. Then the magnetic field at the centre B₂=

In an experiment to determine the temperature coefficient of resistance of a conductor, a coil of wire X is immersed in a liquid. It is heated by an external agent. A meter bridge set up is used to determine resistance of the coil X at different temperatures. The balancing points measured at temperatures t₁=0°C and t₂=100°C are 50 cm and 60 cm respectively. If the standard resistance taken out is S=4Ω in both trials, the temperature coefficient of the coil is

For the reaction, \( A \rightleftharpoons B \), \( E_a = 50 \, \text{kJ/mol} \) and \( \Delta H = -20 \, \text{kJ/mol} \). When a catalyst is added, \( E_a \) decreases by \( 10 \, \text{kJ/mol} \). What is the \( E_a \) for the backward reaction in the presence of the catalyst?  

A current of 3 A is passed through a molten calcium salt for 1 hr 47 min 13 sec. The mass of calcium deposited is : (Molar mass of 1 Ca=40gmol^-1)

Under electrostatic condition of a charged conductor, which among the following statements is true?

Dimensional formula for activity of a radioactive substance is

8.8 g of monohydric alcohol added to ethyl magnesium iodide in ether liberates 2240 cm³ of ethane at STP. This monohydric alcohol when oxidised using pyridinium-chlorochromate, forms a carbonyl compound that answers silver mirror test (Tollens’ test). The monohydric alcohol is :

The maximum volume of the right circular cone with slant height 6 units is

NO₂ gas is :

A uniform electric field E-3×10⁵NC^-1 is acting along the positive Y-axis. The electric flux through a rectangle of area 10cm × 30 cm whose plane is parallel to the Z-X plane is

For the reaction PCI₅ → PCI₃ + Cl₂, rate and rate constant are 1.02×10^-4 mol L^-1s^-1 and 3.4×10^-5s^-1 respectively at a given instant. The molar concentration of PCI₅, at that instant is:

The complex compounds [Co(NH₃)₅SO₄]Br and [Co(NH₃)₅Br]SO₄ are:

A point charge A of +10µC and another point charge B of +20µC are kept Im apart in free space. The electrostatic force on A due to B is \(\overrightarrow{F_1}\), and the electrostatic force on B due to A is \(\overrightarrow{F_2}\). Then

Sodium enthanoate on heating with soda lime give ‘X’. Electrolysis of aqueous solution of sodium ethanoate gives ‘Y’, ‘X’ and ‘Y’ respectively are :

\(α-D-(+)- glucose\) and \(β-D-(+)- glucose\) are:

The biodegradable polymer obtained by polymerisation of Glycine and Aminocaproic acid is:

Which of the following set of polymers are used as fibre?
(i) Teflon
(ii) Starch
(iii) Terylene
(iv) Orlon

Consider the nuclear fission re action  Assuming all the kinetic energy is carried away by the fast neutrons only
and total binding energies of    MeV and 780 MeV respectively, the average kinetic energy
carried by each fast neutron is (in MeV)

Vapour pressure of a solution containing 18 g of glucose and 178.2 g of water at 100°C is :
(Vapour pressure of pure water at 100°C = 760 torr)