A bar magnet held perpendicular to a uniform magnetic field experiences a torque \( T_1 \). By what angle should it be rotated to change the experienced torque to \( 0.5T_1 \)?

What is the shape of a wavefront when light emerging out of a convex lens when a parallel beam of light incident over it ?

The core of a transformer is laminated to:

What is the total energy of electron in the \( n^{th} \) stationary orbit of hydrogen atom ?

Which of the following statements is correct?

Consider a permanent dipole of dipole moment P in a non-uniform electric field E. Which of the following option is correct?

A uniformly charged sphere of \( 80 \text{ } \mu\text{C} \) and radius 2 cm is placed in air.
The electric field intensity at a point 20 cm from the center of the sphere is:

The value of p so that the lines \(\frac{x-1}{-3}=\frac{2 y-2}{2 p}=\frac{z-3}{2}\) and \(\frac{x-1}{-3 p}=\frac{y-1}{4}=\frac{6-z}{5}\) are at right angles is

Match List - I with List - II.

List-I (Birth control methods)	List-II (Features)
(A) Diaphragms	(I) Removal of vas deferens
(B) Lactational amenorrhea	(II) Increase phagocytosis of sperms
(C) Vasectomy	(III) Absence of menstrual cycle and ovulation following parturition
(D) IUDs	(IV) Cover the cervix and blocks the entry of sperm

Choose the correct answer from the options given below :

Arrange the given compounds in order of decreasing oxidation state of nitrogen:
A. \(N_2\)
B. \(NO\)
C. \(HNO_3\)
D. \(NH_4Cl\)
Choose the correct answer from the options given below:

The technology of biogas production was developed in India mainly due to the efforts of -

When Tt x Tt are crossed, how many percent of the offsprings show a recessive phenotype?

Question based on the following passage :
P-Block elements are placed in group 13 to 18 in the periodic table. Group 15 is nitrogen family.
Nitrogen can react with hydrogen, oxygen, halogens etc. It shows multiple oxidation states in its various oxides i.e. \(N_2O, N_2O_3, N_2O_5\) etc. Important allotropic forms of phosphorus are white, red and black phosporus. Various compounds of phosphorus are phosphine, \(PCl_3, PCl_5\) and oxoacids of phosphorus. Oxidation states \(+1\) to \(+5\) are seen in various oxoacids of phosphorus. Group 17 elements are collectively known as halogens. Bond dissociation enthalpy of \(F_2\) is smaller than \(Cl_2\).
The gases present in group 18 are chemically unreactive, they form only few compounds. Neil Bartlett (in 1962) observed the reaction of a noble gas. Since then, many noble gas compounds have been synthesised.
Following statements are given regarding structure of \(N_2O_5\) :
(A) It has an angular structure
(B) It has a planar structure
(C) There are 6 sigma and 2 pi bonds
(D) There are 5 sigma and 2 pi bonds
(E) There are 6 sigma and 3 pi bonds
Choose the correct answer from the options given below :