Physics
On a cold day when the room temperature is 15°C, the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of 15°C, because :

Metals have higher thermal capacity than plastics
Plastics have a lower density than metals
Plastics have a higher thermal conductivity than metals
Metals are good conductors of heat

ANSWER DOWNLOAD EXAMIANS APP

Physics
RADAR is used for:

receiving a signals in a radio receiver.
detecting and locating the position of objects such as Aeroplanes.
locating geostationary satellites.
locating submerged submarines.

ANSWER DOWNLOAD EXAMIANS APP

Physics
When a piece of pure silicon is doped with aluminium, then

The conductivity of the doped silicon piece will remain the same
The doped silicon piece will become p-type
The doped silicon piece will become n-type
The resistivity of the doped silicon piece will increase

ANSWER DOWNLOAD EXAMIANS APP
MORE MCQ ON Physics