YNet StudyHub

1A convex lens of focal length 20 cm forms a real image of a candle on a screen placed 80 cm from the lens. Where is the candle placed?

A 20 cm B 25 cm C 40 cm D 60 cm

2A car moves at a constant speed of 15 m s⁻¹ around a circular track of radius 30 m. What is the magnitude of its centripetal acceleration?

A 0.75 m s⁻² B 1.5 m s⁻² C 3.0 m s⁻² D 7.5 m s⁻²

3A wooden block floats with 1/4 of its volume submerged in water. What is the density of the wood relative to water?

A 0.25 ρ_water B 0.5 ρ_water C 0.75 ρ_water D 1.0 ρ_water

4Which region of the electromagnetic spectrum has the shortest wavelength?

A Infrared B Visible light C Ultraviolet D X‑rays

5When a coil is rotated in a uniform magnetic field, the induced emf is maximum when the plane of the coil is:

A Parallel to the field B Perpendicular to the field C At 45° to the field D At any angle

6A 10 Ω resistor is connected in series with a 5 Ω resistor across a 240 V mains supply. What is the current through the circuit?

A 12 A B 16 A C 20 A D 24 A

7In a cathode‑ray tube, the rays are produced by:

A Protons B Neutrons C Electrons D Photons

8Which of the following statements about X‑rays is false?

A They are produced when high‑energy electrons strike a metal target. B They can ionise atoms. C They have longer wavelengths than visible light. D They are used in medical imaging.

9According to the photoelectric effect, increasing the frequency of incident light while keeping intensity constant will:

A Increase the number of emitted electrons B Increase the kinetic energy of emitted electrons C Decrease the kinetic energy of emitted electrons D Have no effect

10Which type of nuclear decay results in the emission of a beta particle?

A α‑decay B β‑decay C γ‑decay D Positron emission