Answer:
λ = 3.33 m
Explanation:
<u><em>Given:</em></u>
Frequency = f = 9 × 10⁷ Hz
Speed = v = 3 × 10⁸ m/s
<u><em>Required:</em></u>
Wavelength = λ = ?
<u><em>Formula:</em></u>
v = fλ
<u><em>Solution:</em></u>
<em>Putting the givens in the formula</em>
v = fλ
λ = 
λ = 
λ = 0.33 × 10¹
λ = 3.33 m
So, a concave mirror is a mirror that goes inward, thus, making a convex mirror have an outward curvature. Ex: A convex mirror is used at the front of a bus.
Transformer contains two coils: primary and secondary. They allow change of voltage to lower or higher value. In first case we have step-down and in second case we have step-up transformer.
Formula used for transformer is:
Where:N1 = number of turns on primary coilN2 = number of turns on secondary coilV1 = voltage on primary coilV2 = voltage on secondary coil
In a step-down transformer primary coil has more turns than secondary coil. So the ratio 1:38 means that for each turn on secondary coil we have 38 turns on primary coil.
We can solve the equation for V2:
Secondary coil provides voltage of 3.16V.
Answer: (b)
Explanation:
Given
Mass of box 
Applied force 
Friction force 
Box travels a distance of 
time taken 
Net unbalanced force 
Work done by the unbalanced force
Power developed by unbalanced force
Thus, option (b) is correct.
