Two point changes \( - q \) and \( + q \) are located at points \( (0, 0, -a) \) and \( (0, 0, +a) \) respectively. The electric potential of a point \( (0, b, 0) \), where \( b > a \), is :

Three capacitors each of capacitance \( 3 \mu F \) are provided. These cannot be combined to provide the resultant capacitance of:

The magnetic flux passing perpendicular to the plane of a coil is changing according to the equation \( \Phi = 6t^2 + 7t + 1 \) where \( \Phi \) is in mWb and t is in seconds. The magnitude of induced emf at t = 2 s is:

The ground state energy of hydrogen atom is -13.6 eV. The kinetic and potential energies of the electron in this state will be

Identify the basic features of the photon picture of electromagnetic radiation from the following:
(A) Each photon has energy \(E = h\nu\) in vacuum.
(B) Photons are electrically neutral and are not deflected by electric and magnetic fields.
(C) All photons of light of a particular frequency \(\nu\) or wavelength \(\lambda\) have the same energy and momentum.
(D) If the intensity of light of a given wavelength is increased, there is an increase in the number of photons incident on a given area in a given time.
Choose the correct answer from the options given below:

When a slab of insulating material 4 mm thick is introduced between the plates of a parallel plate capacitor of separation 4 mm, it is found that the distance between the plates has to be increased by 3.2 mm to restore the capacity to its original value. The dielectric constant of the material is :

A resistor develops 200 J of thermal energy in 5 s when a current of 2 A is passed through it. If the current is measured to 5 A, what will be the energy developed in 12 s ?

In the depletion region of an unbiased p-n junction diode there are

Read the passage carefully and answer the following questions
Aldehydes, carboxylic acids and ketones are widespread in the animal and plant kingdoms. They play a pivotal role in various biochemical processes of life. Their presence in nature adds fragrance and flavor. These compounds are widely used in food products, pharmaceuticals, paints, resins and other important product industries. These compounds are prepared by various laboratory methods, which mainly include oxidation, formylation, acylation and reduction. Due to the polar nature of the carbonyl group in aldehydes and ketones, they can exhibit different reactions like nucleophilic addition. They do exhibit redox and various condensation reactions which lead to the formation of various important compounds. On the other hand, the carboxylic acids are mainly prepared by oxidation and hydrolysis of different compounds. The carboxylic acid consists of a carbonyl group and the hydroxy group (attached to the carbonyl carbon atom). This makes it possible for the carboxylic acid to participate in various chemical reactions which involve cleavage of the C-OH bond and the O-H bond along with the reactions involving the complete - COOH group.
Identify the incorrect statement for Cannizaro reaction.

The value of a washing machine purchased two years ago depreciates at the annual rate of 10%. If its present value is ₹ 50,000, then its value after two years will be :

The function \(f(x)=x+\cot ^{-1} x\) is increasing in the interval:

A closely wound coil of 50 turns and radius 15 cm carries a current of 3 A. The magnetic moment of the coil is:

A bulb is rated 40 W for a 220 V supply. The peak voltage of the supply is: