Which frequency is used by elephants to communicate with each other:
Zero frequency
Low frequency
Medium frequency
High frequency
Watt is equal to:
Coulomb per second
Newton per second
Volt per second
Joule per second
The refractive index of ice is:
1.00
1.33
1.31
2.42
The unit of spring constant is:
Nm2
Nm-1
The substances which do not have free electrons are called:
Insulators
Conductors
Semiconductors
None of these
The point through which rays of light pass after reflection from concave mirror is called principal:
Focus
Circle
Axis
Radius