The dissociation constant of and acid HA is 1x10^-5.The pH of 0.1 molar solution of the acid will be :

1) Five
2) Four
3) Three
4) One.

An open container has net 10 gm mass of a radioactive material. The net mass in the container after two mean lives is approximately:

1) 1.35 gm
2) 2.5 gm
3) 10 gm
4) 5 gm

An object is resting at the bottom of two strings which are inclined at an angle of 120° with each other. Each string can withstand a tension of 20 N. The maximum weight of the object that can be supported without breaking the string is

1) 5 N

2) 10 N

3) 20 N

4) 40 N

A circuit has a self-inductance of 1H and carries a current of 2A. To prevent sparking, when the circuit is switched off, a capacitor which can withstand 400V is used. The least capacitance of capacitor connected across the switch must be equal to

1) 50μF

2) 25μF

3) 100μF

4) 12.5μF

Which one of the following is not correct statement?

1) Herbarium houses dried, pressed and preserved plant specimens.

2) Botanical gardens have collection of living plants for reference

3) A museum has collection of photographs of plants and animals

4) Key is a taxonomic aid for identification of specimens

The current classification system was devised by:
 1) Aristotle
 2) Plato
 3) Linneaus
 4) Darwin
 

Grey cresent is present in

 (1) Fertilised egg of frog
 (2) brain of rabbit
 (3) retine of cockroach
 (4) eye of frog

The organ in the human body that has both voluntary and involuntary muscles is

1) trachea
2) oesophagus
3) lungs
4) heart

Sprian is caused by the excessive pulling of
1. Muscles
2. Tendons
3. Ligaments
4. Nerve fibres

Quiescent centres are found in

 1) all types of meristems  2) only in apical meristems
 3) only in root apex         4) only in shoot apex