Answer:
(a) convex mirror
(b) virtual and magnified
(c) 23.3 cm
Explanation:
The having mirror is convex mirror.
distance of object, u = - 20 cm
magnification, m = 1.4
(a) As the image is magnified and virtual , so the mirror is convex in nature.
(b) The image is virtual and magnified.
(c) Let the distance of image is v.
Use the formula of magnification.

Use the mirror equation, let the focal length is f.

Radius of curvature, R = 2 f = 2 x 11.67 = 23.3 cm
The only force on the system is the mass of the hoop F net = 2.8kg*9.81m/s^2 = 27.468 N The mass equal of the rolling sphere is found by: the sphere rotates around the contact point with the table.
So by applying the theorem of parallel axes, the moment of inertia of the sphere is computed by:I = 2/5*mR^2 for rotation about the center of mass + mR^2 for the distance of the axis of rotation from the center of mass of the sphere.
I = 7/5*mR^2 M = 7/5*m
Therefore, linear acceleration is computed by:F/m = 27.468 / (2.8 + 1/2*2 + 7/5*4) = 27.468/9.4 = 2.922 m/s^2
Answer:
1) ELECTRO MAGNET
2) B
3) -AMOUNT OF ELECTRICITY OF THE POWER SOURCE
- AMOUNT OF COIL WRAPPED UP TO THE NAIK
-CONDUCTIVITY OF THE MEDIUM
Answer:
Spring C
Explanation:
According to Hooke's law, a force require to compress or extend a spring is directly proportional to the distance from its mean position.
The force of compression or expansion of the spring is given by the formula,
F = k x
Where,
k - spring constant. It is the constant value of the particular spring
x - distance of expansion or compression from mean position.
The x value of different spring,
A = 25 cm
B = 10 cm
C = 100 cm
D = 1 cm
The highest value of x for the same mass has the smallest spring constant according to the equation.
Hence, C has the smallest spring constant.