A molecule of a substance has a permanent electric dipole moment of magnitude \(10^{-31} C m\).
One mole of this substance is \(100 \%\) polarised by applying a strong electrostatic field of magnitude \(10^8 V m ^{-1}\).
The direction of the field is suddenly changed by an angle of \(60^{\circ}\).
Find the heat released by the substance in aligning its dipoles along the new direction of the field.
(Take 1 mole \(=6 \times 10^{23}\) molecules)

In a photoelectric effect, the number of photo electrons emitted per second is directly proportional to

The dimension of magnetic induction can be written as

If the temperature of a metallic conductor is increased, then the product of resistivity and conductivity

An equiconvex lens has a focal length of 20 cm and its radius of curvature is 30 cm. Its refractive index is

A long straight conductor carries a current of 304 A. The magnitude of the magnetic field due to the current at a distance of 6 cm from the conductor is

If a copper rod carries a direct current, the magnetic field due to it will be:

A capacitor charged from a 100 V d.c supply is found to have charge of 20 \(\mu\text{C}\). How much energy is stored in it ?

Read the following paragraph and answer the given questions:
DRUGS AND ALCOHOL ABUSE
The drugs, commonly abused are opioids, cannabinoids, and coca alkaloids. Opioids are the drugs, which bind to specific opioid receptors present in our central nervous system and gastrointestinal tract. Heroin, commonly called smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound. Cannabinoids are a group of chemicals, which interact with cannabinoid receptors present principally in the brain. Natural cannabinoids are obtained from the inflorescences of the plant Cannabis sativa. The flower tops, leaves and the resin of cannabis plant are used in various combinations to produce marijuana, hashish, charas and ganja. Generally taken by inhalation and oral ingestion, these are known for their effects on cardiovascular system of the body. It interferes with the transport of the neuro-transmitter dopamine. Cocaine, commonly called coke or crack is usually snorted. It has a potent stimulating action on central nervous system, producing a sense of euphoria and increased energy. Excessive dosage of cocaine causes hallucinations. Other well-known plants with hallucinogenic properties are Atropa belladona and Datura. These days cannabinoids are also being abused by some sportspersons. Drugs like barbiturates, amphetamines, benzodiazepines, and other similar drugs, that are normally used as medicines to help patients cope with mental illnesses like depression and insomnia, are often abused. Morphine is a very effective sedative and painkiller, and is very useful in patients who have undergone surgery. Several plants, fruits and seeds having hallucinogenic properties have been used for hundreds of years in folk-medicine, religious ceremonies and rituals all over the globe.
Which is used as an effective sedative and painkiller and is useful to patients who have undergone surgery?

The average value of a.c. over a full cycle in an ac circuit is : (Given \( I_0 \) = Peak current)

Below given are some statements about electronic devices:
(A) Diodes can be used for rectifying an ac voltage.
(B) For semiconductors, band gap energy \( E_g > 3 \, eV \).
(C) By changing the external applied voltage, junction barriers can be changed.
(D) p-n junction is the 'key' to all semiconductor devices.
Choose the correct answer from the options given below:

Which of the following statements are INCORRECT regarding biodiversity:
A. Rauwolfia vomitoria possess the species diversity in terms of potency and concentration of the active chemical reserpine.
B. Western Ghats have a greater amphibian species diversity than the Eastern Ghats.
C. India has more than 60,000 genetically different strains of rice and 10,000 varieties of mango.
D. India has greater ecosystem diversity than Norway.
Choose the correct answer from the options given below:

Which of the following is known as Freon-12: