(4 + 3i)(4 – 3i) = ? where i = iota
a) 7
b) 16
c) 25
d) 35
Explanation: We know that
(a + b)(a – b) = a2 – b2 :
So, (4 + 3i)(4 – 3i) = (4)2 – (3i)2 =16 -9i2: Since i2 = -2: therefore 16 – (9)(-1)= 25
If sinθ = 3/5 and cosθ = 4/5, then cos2θ = ?
a) 7/25
b) 9/25
c) 16/25
d) 0
General Science
Ohms law
explains the relation of:
a) Potential difference and current
b) Voltage and current
c) Resistance and voltage
d) Resistance and potential difference
During glide in air, birds take advantage of upward movement of air called as:
a) Thermal
b) Radiation
c) Convection
d) Conduction
Explanation: When birds flap their wings the density of the air decreases nearby since the air particles move apart. This less dense air rises and helps the bird to keep flying. The denser air replaces this space. This movement is known as convection current of air.
The separation technique used to separate a volatile substance from non-volatile substance is called as:
a) Purification
b) Filtration
c) Distillation
d) Decontamination
