When the electron in a hydrogen atom jumps from the 2nd orbit to the 1st orbit, the wavelength of the radiation emitted is \(\lambda\).
When the electron jumps from the 3rd orbit to the 1st orbit, the wavelength of emitted radiation is:

An object is placed at a distance of 10 cm from a concave mirror of focal length 15 cm. The magnification of the image is

Which of the following statement(s) is/are correct?
(A) The power of a lens is the ability of the lens to converge or diverge the incident rays.
(B) S.I unit of the power of a lens is dioptre while focal length is in centimetres
(C) For a lens of larger focal length, power is smaller
(D) In any combination of lenses, the power of combination is not algebraic addition of power of combined lenses
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An electron gun emits 3 \(\times 10^{16}\) electrons per second. What electric current does this correspond to ?

The energy in the sun is generated mainly by:

A convex lens of glass (n = 1.5) has a focal length 18 cm in air. When it is immersed in water (n = 4/3) the focal length increases to:

The separation between the plates of a charged parallel plate capacitor is increased. Which of the following quantities will change?
(A) charge on the capacitor plates
(B) potential difference across the capacitor
(C) energy of the capacitor
(D) energy density between the plates of the capacitor
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Which of the following is an essential amino acid?

Read the passage carefully. Attempt the questions.
In our body, cell growth and differentiation is highly controlled and regulated. In cancer cells, there is breakdown of these regulatory mechanisms. Cancerous cells just continue to divide giving rise to masses of cells called tumors. Benign tumors normally remain confined to their original location. The malignant tumors, on the other hand are a mass of proliferating cells. These cells actively divide and starve the normal cells by competing for vital nutrients. Cells sloughed from such tumors reach distant sites through blood, and wherever they get lodged in the body, they start a new tumor there. This property is called metastasis. Transformation of normal cells into cancerous cells may be induced by physical, chemical or biological agents called carcinogens.
Cancer is caused by:
A. Carcinogens
B. Protein rich foods
C. Primary lymphocytes
D. Oncogenes
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If the random varible X has the following probability distribution:

X	0	1	2	otherwise
P(X)	K	3K	5K	0

X = 0, P(X) = k; x = 1, P(x) = 3k; X = 2, P(x) = 5k; otherwise, P(X) = 0
Match List - I with List - II

List - I	List - II
(A) k	(I) \(\frac{13}{9}\)
(B) E(X)	(II) \(\frac{4}{9}\)
(C) P(X ≤ 1)	(III) \(\frac{8}{9}\)
(D) P(1 ≤ X ≤ 2)	(IV) \(\frac{1}{9}\)

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Answer the question on the basis of passage given below :
Formaldehyde is the first member of the aldehydic series. It is present in green leaves of plants where its presence is supposed to be due to the reaction of \(CO_2\) with water in the presence of sunlight and chlorophyll. Commercially, formaldehyde is obtained by the controlled oxidation of methane in the presence of molybdenum oxide (\(MoO\)) acting as a catalyst. Formaldehyde is a constituent of a number of polymers also called resins. These are non volatile solids or semi solids which are obtained directly from certain plants and can be synthesized in the laboratory.
Question: How is formalin useful?

Two polaroids \( P_1 \) and \( P_2 \) are set in crossed positions. A third polaroid \( P_3 \) is placed between the two making an angle \( \alpha \) with the axis passing from the first polaroid \( P_1 \). In what orientation will the transmitted intensity be maximum?

In the systematic study of the photoelectric effect experiment, the stopping potential depends (for a given metal):