If silicon is doped with phosphorus, what type of semiconductor material will be formed?
Zener material
P-n junction
n-type
p-type
Correct answer is C
When silicon is doped with a trivalent atom. A p-type semi-conductor will be formed when silicon is doped with a pentavalent atom such as arsenic, a n-type semi-conductor will be formed
Phosphorous is a pentavalent element, so it will produce a o -type semi-conductor
5
4
3
2
Correct answer is C
When two mirror are inclined at an angle θ, the number of images formed, n = \(\frac{360}{\theta}\) − 1
∴ since \(\theta\) = 90o
∴ \(\frac{360}{\theta}\) − 1
= 4 − 1
= 3
The action of blotting paper on ink is due to
diffusion
osmosis
capillarity
surface tension
Correct answer is C
Capillarity is the tendency of a liquid to rise or fall in a narrow tube and it explains why a blotting paper absorbs ink
What is the speed of a body vibrating at 50 cyclic per second
100 πrads\(_{−1}\)
200 πrads\(_{−1}\)
50 πrads\(_{−1}\)
400 πrads\(_{−1}\)
Correct answer is A
1 cycle = 360° = 2π rad
∴ 50 cycle = 2 π rad × 50 = 100 πrad
∴ = angular speed = 50 cycles per seconds = 100 π rads\(_{−1}\)
The instrument to measure the relative density of liquid is
thermometer
hydrometer
spring balance
beaker
Correct answer is B
Thermometer is used to measure temperature
Hydrometer is used to measure relative density of liquid.
Spring balance is used to measure the weight of an object
Beaker is used to measure or take volume of a liquid