Three capacitors each of capacitance 9 pF are connected in series. The capacitance of the combination would be :

Which of the following statements are correct ?
(A) Electrostatic field lines form closed loops.
(B) In an electric dipole, the direction from charge to q is the direction of the dipole.
(C) Water molecule is an example of polar molecule.
(D) The electric field due to a uniformly charged thin shell is zero at some points inside the shell.
(E) Electrostatic force is conservative in nature.
Choose the correct answer from the options given below :

In a transistor :
(A) one of the outer layers is heavily doped and is called collector
(B) one of the outer layers is heavily doped and is called emitter
(C) the middle layer is very lightly doped and is called base
(D) one of the outer layer is moderately doped and is called emitter
(E) one of the outer layer is moderately doped and is called collector
Choose the correct answer from the options given below :

Match List-I with List-II

List-I	List-II
(A) The standard resistance coil	(I) Nickel-chromium alloy
(B) The connecting wire	(II) tin-lead alloy
(C) The heating wire	(III) copper metal
(D) The fuse wire	(IV) copper manganese nickel alloy

Choose the correct answer from the options given below:

Which of the following statements are true about electromagnetic waves?
(A) Accelerated charges radiate electromagnetic waves.
(B) The frequency of the electromagnetic wave equals the frequency of oscillation of the charge.
(C) No material medium is involved in the vibrations of the electric and magnetic fields.
(D) Electromagnetic waves of different wavelengths have different velocities in free space/vacuum.
Choose the correct answer from the options given below:

A proton and an alpha particle of the same velocity enter in turn a region of uniform magnetic field, acting perpendicular to their direction of motion. The ratio of the radii of the circular paths described by the particles, respectively, would be

A long straight wire of radius 'a' carries a steady current 'I'. The current is uniformly distributed across its area of cross-section. The ratio of magnitude of magnetic fields \( B_1 \) at a distance a/2 and \( B_2 \) at a distance 2a from the axis of the wire is :

A relation \(R\) on the set \(A=\{1, 2, 3, \ldots, 13, 14\}\) defined as \(R=\{(x, y) : 3 x-y=0\}\) is

The IUPAC name of allylamine is.

In a 500 metres race, the ratio of speeds of two participants Meena and Kamal is 4: 5 respectively. If Meena has a start of 200 metres, find the distance by which Meena wins.

In an AC generator, a coil of 20 turns each with area \( 2 \times 10^{-2} \text{ m}^2 \) is rotated at 50 revolutions per sec in a uniform magnetic field of 2.5 T. The maximum induced emf produced is:

What happens when light is refracted into a medium ?

Read the passage carefully and answer the questions
The chemical reactions proceed at different rates which depend on various factors like concentration, temperature, etc. Rate law is an expression which relates the rate of reaction with concentration of various reacting species in the reaction. For a first order reaction, the concentration of the reactant after time \(t\) is related with its initial concentration by the relation, \(C=C_0 e^{-k t}\). The rate constants for different orders have different expressions. For a first order reaction, \(k=\frac{2.303}{t} \log \frac{a}{a-x}\), where \(a\) is the initial concentration and \(x\) is the extent of reaction.
The quantity k in a rate law expression is