Question

Q1. which of the following statement is true-
a) image of virtual obj. is called virtual image
b) if the reflecting rays are converging we get a real image
c) if the incident rays are converging we get real object
d) if image is virtual the corresponding object is called a virtual obj.

Q2. a concave mirror has a radius of curvature of 30cm , then its focal length would be
a) 60cm
b) 30cm
c) 15cm
d) 7.5cm
pls explain thoroughly through working

Q3. when a soung wave travels from air to water, the quantity tht remains same is its
a) wave length
b) frequency
c)velocity
d) amplitude

Answer 1

3)b
2)d
1)c
this are the answers

Answer 2

q-2 answer is 15cm,f=r/2