Physics concepts such as aerodynamics and air resistance were no longer dry theories found in books for Secondary 3 student Gabriel Ong last Wednesday.

Instead, he had to apply such concepts when he had a go at learning how to make a solar-powered car.

"The aim was to modify our car so that it would go the fastest," said the 15-year-old, who used materials such as plastic bottles, solar panels and wheels to build his vehicle.

"I tried to make the shape of the car as streamlined as possible, like flattening the bottom of the bottle and closing its hole with masking tape to prevent air from coming in."

The Damai Secondary School student was one of more than 800 students from 11 secondary schools who had a glimpse of the practical side of engineering at Singapore Polytechnic. They tried their hand at activities such as programming robots and designing a model aircraft as part of an effort to excite secondary school students about engineering.

This comes as fewer top students choose engineering, and opt instead for more lucrative or interesting courses in business, media studies and the life sciences.

The Ministry of Education said in response to queries that the polytechnics had an intake of 7,300 engineering students last year.

A spokesman said about 30 per cent of polytechnic students enrolled in engineering courses over the past few years, and this figure has remained "fairly stable".

This year, the annual Engineering Discovery event - jointly organised by the five polytechnics for the 13th time - included for the first time a series of workshops for students to try simple projects.

Ms Wendy Leck, who headed the organising committee, said the five workshop themes - green technologies, aircraft design, robots, smart devices and healthcare - were chosen for their relevance to Singapore's growing needs.

"We tried to link the workshops back to the physics concepts in secondary school, so students see that what they learn is relevant," said Ms Leck, a senior lecturer from Singapore Polytechnic's School of Electrical and Electronic Engineering.

"The aim was to give them a big picture of engineering and show them how broad it is, from solar energy all the way to robotics."

Engineering is currently Gabriel's second choice after business management.

"It was pretty interesting to see some of these concepts in real life... but I haven't really thought of what I want to do for my career," he said. "Principles of accounts is my best subject so I think I'm more suited for business."

At the event, each polytechnic featured two interactive projects done by their engineering students, from robots to help the elderly in tasks such as physical exercise, to an app that detects hearing loss. Students also attended a talk on the educational and career options for engineers.