The Black Forest Mountain in Europe belongs to which class of mountains?

a- Fold mountains

b- Block mountains

c- Volcanic mountains

d- Residual mountains

The fertile black soil, most suitable for the cultivation of Cotton is known as:

(A) Bhangar

(B) Bhabar

(C) Lom

(D) Regur

The density of water is maximum at:

(A)  $2^0$C

(B) $4^0$ C

(C) $6^0$ C

(D) $8^0$ C

The 'Universal donor' belongs to the blood group:

(A) A

(B) B

(C) AB

(D) O

The difference between musical sound and noise is due to the:

Heat and smoke in a kitchen are transferred through the chimney by:

(A) conduction

(B) suction

(C) convection

(D) radiation

When a source of sound waves moves towards an observer at rest, the pitch of the note heard by the observer is higher. This phenomenon is known as:

(A) Doppler effect

(B) Resonance

(C) Acoustics

(D) Reverberation

Vinegar is the trade name of:

(A) Chloroform

(B) Acetic acid

(C) Phenol

(D) Carbon tetrachloride

The hormone that helps child birth by contracting the uterus is:

(A) Thyroxine

(B) Insulin

(C) Oxytocin

(D) Calcitonin