Is it correct to say that any two right angles are congruent? Give reasons to justify your answer.

In Delta ABC and Delta PQR,angleA=angleQ and angleB=angleR. Which side of Delta PQR should be equal to side AB of Delta ABC , so that the two triangle are congruent ? Give reason for your answer.

In Delta ABC and Delta PQR,angleA=angleQ and angleB=angleR. Which side of Delta PQR should be equal to side BC of Delta ABC ,so that the two triangle are congruent ? Give reason for your answere.

Can a triangle have two obtuse angles ? Give reason for your answer.

Name the wave used in sonar. Give reason to your answer.

Can all the angles of a quadrilateral be right angles ? Give reason for your answer.

Which cools faster, Land or Water? Give a reason for your answer.

Answer the following: (i) Obtain the expression for the cyclotron frequency. (ii) A deuteron and a proton are accelerated by the cyclotron. Can both be accelerated with the same oscillator frequency ? Give reason to justify your answer.

Write one main difference between asexual and sexual mode of reproduction. Which species is likely to have comparatively better chances of survival - the one reproducing asexually or the one reproducing sexually ? Give reason to justify your answer.

Can all the angles of a quadrilateral be acute angles ? Give reason for your answer.

Consider the following circuit : What would be the readings of the ammeter and the voltmeter when key is closed ? Give reason to justify your answers .